Heteromeric proteins comprising three heteromerization improving substitution, production, combinations and applications thereof

Abstract

The present invention generally relates to the production and use of antigen-binding proteins. The invention relates to heteromeric antigen-binding proteins, their production and their use. In particular the invention relates to the combination of an antigen-binding protein binding to a peptide according to SEQ ID NO: 57 or to the peptide according to SEQ ID NO: 57 bound to a major histocompatibility complex (MHC) protein and an antigen-binding protein binding to a peptide according SEQ ID NO: 58 or to the peptide according to SEQ ID NO: 58 bound to a major histocompatibility complex (MHC) protein and optionally one or more further antigen-binding proteins. Furthermore, the invention relates to heteromeric antigen-binding proteins with improved heterodimerisation properties and correspondingly improved production properties. The invention also relates to co-expression of at least two heteromeric antigen-binding proteins. The invention further relates to heteromeric antigen-binding proteins for use in the treatment of diseases, in particular cancer, optionally wherein nucleic acids encoding said antigen-binding proteins are administered to the subject.

Description

[0001]New PCT Patent Applica�on Applicant: Imma�cs Biotechnologies GmbH Imma�cs Ref.: P303PC00 Heteromeric proteins, produc�on, combina�ons and applica�ons thereof The present inven�on generally relates to the produc�on and use of an�gen-binding proteins. The inven�on relates to heteromeric an�gen-binding proteins, their produc�on and their use. In par�cular the inven�on relates to the combina�on of an an�gen-binding protein binding to a pep�de according to SEQ ID NO: 57 or to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a pep�de according SEQ ID NO: 58 or to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen- binding proteins. Furthermore, the inven�on relates to heteromeric an�gen-binding proteins with improved heterodimerisa�on proper�es and correspondingly improved produc�on proper�es. The inven�on also relates to co-expression of at least two heteromeric an�gen- binding proteins. The inven�on further relates to heteromeric an�gen-binding proteins for use in the treatment of diseases, in par�cular cancer, op�onally wherein nucleic acids encoding said an�gen-binding proteins are administered to the subject. Proteins serve as the building blocks of life, orchestra�ng a mul�tude of physiological processes within the human body. Leveraging their inherent biological ac�vity, researchers exploit protein-based therapeu�cs to intervene in disease pathways at the molecular level, offering promising solu�ons for condi�ons ranging from cancer and autoimmune disorders to metabolic diseases and infec�ons. Bispecific proteins represent an emerging innova�ve class of protein-based therapeu�cs designed to simultaneously target two different epitopes or proteins, thereby offering enhanced therapeu�c efficacy and versa�lity compared to tradi�onal monospecific drugs. Bispecific proteins hold immense promise for trea�ng a wide array of diseases, including cancer, autoimmune disorders, and infec�ous diseases. An example for bispecific molecules that hold tremendous poten�al to treat e.g. cancer is the so called T cell Engaging Receptor (TCER®) format developed by the applicant of the present inven�on; see e.g. WO 2019 / 012138 A1 herein incorporated. TCERs® are off-the-shelf biologics that leverage the body’s immune system by redirec�ng and ac�va�ng T cells towards cancer cells presen�ng specific tumor an�gens. These novel biologics are engineered to allow T cells in the body to become ac�vated and atack the tumor, regardless of the T cells’ intrinsic specificity. A TCER® contains two polypep�de chains harboring a T cell-recrui�ng an�body domain and a pHLA-binding TCR domain. Furthermore, each of the polypep�de chains contains a Fc domain. The development and u�liza�on of such protein-based therapeu�cs is crucial for thefield of immunotherapy. However, the full spectrum of effectiveness of these promising drugs has not yet been recognized. For example, highly effective combination therapies involving immunotherapy are still not standard. Accordingly, there is a need for means and methods for additional effective cancer treatments. Thus, the technical problem underlying the present invention is the provision of means and methods to treat cancer. The technical problem is solved and the above mentioned needs are addressed by the provision of the embodiments characterized in the claims and as provided herein below. The patent applica�ons EP24174662.7, EP24199013.4, EP25151617.5, EP24213284.3 and EP25166821.6 the preliminary results of a Phase 1first-in-human clinical trials that tests the efficiency and safety of the bispecific an�gen-binding molecules PRAME-004 TCER® and MAG- 003 TCER® as monotherapy. Said molecules show excellent an�-tumor ac�vity with acceptable side effects against different cancer types. In the appended Examples of the present applica�on the inventors found surprisingly and unexpectedly that a synergis�c an�-cancer effect is observed when a MAG-003 targe�ng TCER® and a PRAME-004 targe�ng TCER® are combined (see Example 4). Accordingly, the present inven�on provides a combina�on of the powerful an�-cancer molecules PRAME-004 TCER® and MAG-003 TCER® to allow treatment of a wide range of cancer types. In par�cular the inven�on relates to an an�gen-binding protein binding to a pep�de according to SEQ ID NO: 57 or to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a pep�de according SEQ ID NO: 58 or to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins for use as medicine, in par�cular for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. The above men�oned and herein described an�gen-binding proteins may be produced separately and administered in combina�on to a pa�ent in need thereof as produced proteins. The skilled person understands that “combina�on” does not necessarily mean that the an�gen-binding proteins are combined into one pharmaceu�cal composi�on and administered as one pharmaceu�cal composi�on but that “combina�on” is used herein in the broadest sense and refers to at least two therapeu�cally ac�ve drugs or composi�ons which may be administered or co-administered, simultaneously, in either separate or combined formula�ons, or sequen�ally at different�mes separated by minutes, hours or days, but in some way act together to provide the desired therapeu�c response. It can be desirable to administer the to be combined an�gen-binding proteins not as separately produced proteins but encoded by nucleic acids. In other words, it may be beneficial to administer to the pa�ent nucleic acid(s) encoding the an�gen-binding proteins so that an�gen- binding proteins are produced by the cells of the pa�ent. However, expressing two or more heterodimeric an�gen binding proteins in the same produc�on system can present significant challenges. A primary concern is the poten�al for mispairing between subunits of different heterodimers, leading to the forma�on of non-na�ve or dysfunc�onal complexes. This mispairing can compromise the quality, efficacy, and safety of the therapeu�c product, posing substan�al hurdles for clinical use. For example, WO2013 / 157953 and WO2013 / 157954 describe charge changing amino acid subs�tu�ons in an�body-derived CH3-domain that facilitate heterodimerisa�on of proteins harboring said domains. However, further improvements are required. Accordingly, there is a need for means and methods that allow the correct assembly of heteromeric proteins, in particular heterodimeric proteins. Thus, the present invention also provides means and methods that allow the correct assembly of heteromeric proteins, in particular heterodimeric proteins. Specifically, the inventors developed CH3-domains that convey excellent mul�meriza�on, in par�cular heterodimerisa�on proper�es to proteins comprising said domains. Accordingly, the present inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. As illustrated in the appended Example the present inventors surprisingly and unexpectedly found that the combina�on of a disulphide bridge with certain charge changing amino acid subs�tu�ons improves yield and stability of a heterodimeric protein. Example 1 in combina�on with Table 3 shows that a heterodimeric an�gen-binding protein comprising the claimed charge changing amino acid subs�tu�ons and the claimed ar�ficial disulphide bridge provided increased yield, increased heterodimerisa�on and improved stability. Furthermore, Example 2 in combina�on with Table 4 shows that said molecule can be co-expressed with another heterodimeric protein without forma�on of incorrectly assembled dimers. This was unexpected because the introduc�on of a disulphide bridge in molecules having other charge changing amino acid subs�tu�ons even reduced yield and heterodimerisa�on (see e.g. the molecule TPP-8629 in Table 3). That was further confirmed in Example 3 where it is shown that even when a Strep-Tag II is used for purifica�on (i.e. na�ve purifica�on) up to 96% of the co- expressed heterodimeric an�gen-binding proteins are correctly assembled. Accordingly, it is made plausible herein that MAG-003 and PRAME-004 targe�ng an�gen-binding proteins can be combined for an�-cancer therapy. Accordingly, the inven�on provides combina�ons of specific amino acid subs�tu�ons in CH3 domains that convey excellent proper�es to heteromeric proteins for produc�on an co- expression. In the following, the inven�on is described in more detail. In par�cular, the inven�on relates to the following items. 1. An an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. 2. The an�gen-binding protein of item 1, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and the amino acid variant Y349C. The an�gen-binding protein of item 1 or 2, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant Y349C. The an�gen-binding protein of any one of items 1 to 3, wherein thefirst and second polypep�de specifically bind to each other. The an�gen-binding protein of any one of items 1 to 4, wherein the amino acids subs�tuted in thefirst polypep�de interact with the subs�tuted amino acids in the second polypep�de. The an�gen-binding protein of any one of items 1 to 5, wherein the an�gen-binding protein is a bispecific, trispecific or mul�specific an�gen-binding protein, preferably a bispecific an�gen-binding protein. The an�gen-binding protein of any one of items 1 to 6, wherein the an�gen-binding protein comprises afirst binding domain and a second binding domain. The an�gen-binding protein of item 7, wherein thefirst binding domain specifically binds to a cell surface molecule of a human immune cell and / or the second binding domain specifically binds to an MHC-associated pep�de epitope. The an�gen-binding protein of item 7 or 8, wherein thefirst and / or second binding domain comprises or consists of (an) an�body(ies) or (a) func�onal fragment(s) or deriva�ve(s) thereof. The an�gen-binding protein of any one of items 7 to 9, wherein thefirst and / or second binding domain comprises or consists of (a) T cell receptor(s) (TCR) or (a) func�onal fragment(s) or deriva�ve(s) thereof. The an�gen-binding protein of any one of items 7 to 10, wherein thefirst binding domain comprises or consists of an an�body an�gen binding site (VD). The an�gen-binding protein of any one of items 7 to 11, wherein the second binding domain comprises or consists of a TCR an�gen binding site (VR). The an�gen-binding protein of item 11 or 12, wherein one polypep�de comprises the an�body variable light chain domain (VL) of the an�gen binding site (VD) and the other polypep�de comprises the an�body variable heavy chain domain (VH) of the an�gen binding site (VD). The an�gen-binding protein of any one of items 11 to 13, wherein one polypep�de comprises the TCR alpha variable domain (Vα) of the an�gen binding site (VR) and the other polypep�de comprises the TCR beta variable domain (Vβ) of the an�gen binding site (VR). The an�gen-binding protein of item 13 or 14, wherein one polypep�de comprises the an�body variable light chain domain (VL) and the TCR beta variable domain (Vβ) and the other polypep�de comprises the an�body variable heavy chain domain (VH) and the TCR alpha variable domain (Vα). The an�gen-binding protein of item 13 or 14, wherein one polypep�de comprises the an�body variable light chain domain (VL) and the TCR alpha variable domain (Vα) and the other polypep�de comprises the an�body variable heavy chain domain (VH) and the TCR beta variable domain (Vβ). The an�gen-binding protein of any one of items 1 to 16, wherein thefirst polypep�de further comprises a CH2 domain and / or the second polypep�de further comprises a CH2 domain. The an�gen-binding protein of item 17, wherein in one polypep�de the CH2 domain and the CH3 domain form a Fc domain FC1 and / or in the other polypep�de the CH2 domain and the CH3 domain form a Fc domain FC2. The an�gen-binding protein of any one of items 1 to 18, wherein thefirst polypep�de and the second polypep�de are on separate polypep�de chains or are connected by a linker. The an�gen-binding protein of any one of items 13 to 19, wherein thefirst polypep�de comprises a structure represented by the formula: V1-V2 [I]; and the second polypep�de comprises a structure represented by the formula: V3-V4 [II]; wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The an�gen-binding protein of any one of items 13 to 20, wherein the variable domains are connected by linkers. The an�gen-binding protein of any one of items 13 to 21, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2 [III]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4 [IV]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The an�gen-binding protein of any one of items 13 to 22, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 [V]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 [VI]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The an�gen-binding protein of any one of items 13 to 23, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-L3-FC1 [VII]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-L4-FC2 [VIII]; wherein L1, L2, L3 and L4 are linkers and may be the same or different, and wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The an�gen-binding protein of any one of items 21 to 24, wherein the linkers L1, L2, L3 and / or L4 comprise or consist of SEQ ID NO: 16 (GGGSGGGG). The an�gen-binding protein of any one of items 18 to 25, wherein FC1 and / or FC2 further comprise a hinge region, preferably wherein the hinge region comprises or consists of SEQ ID NO: 15 (EPKSS) or SEQ ID NO: 92 (EPKSC). The an�gen-binding protein of any one of item 18 to 26, wherein the FC1 and / or FC2 comprises at least one effector func�on silencing muta�on at a residue selected from posi�ons 233, 234, 235, 236, 297 and 331, preferably wherein said effector func�on silencing muta�on is generated by replacing at least one residue in posi�on 233, 234, 235, 236, and 331 with the corresponding residue derived from lgG2 or lgG4. The an�gen-binding protein of any one of items 18 to 27, wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1, 39, 88 or 90 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 39, 88 or 90; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2, 40, 89 or 91 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 40, 89 or 91. The an�gen-binding protein of any one of items 13 to 28, wherein the an�body variable light chain domain (VL) and the an�body variable heavy chain domain (VH) associate to form a func�onal an�body an�gen binding site (VD). The an�gen-binding protein of any one of items 14 to 29, wherein the TCR alpha variable domain (Vα) and the TCR beta variable domain (Vβ) associate to form a func�onal TCR an�gen binding site (VR). The an�gen-binding protein of any one of item 8 to 30, wherein the cell surface molecule is known to induce the ac�va�on of the immune cell, or is at least one selected from the group consis�ng of immune response-related molecules, CD3, such as the CD3γ, CD3δ, and CD3ε chains, CD4, CD7, CD8, CD10, CD11b, CD11c, CD14, CD16, CD18, CD22, CD25, CD28, CD32a, CD32b, CD33, CD41 , CD41b, CD42a, CD42b, CD44, CD45RA, CD49, CD55, CD56, CD61, CD64, CD68, CD94, CD90, CD117, CD123, CD125, CD134, CD137, CD152, CD163, CD193, CD203c, CD235a, CD278, CD279, CD287, Nkp46, NKG2D, GITR, FcεRI, TCRa / β, TCRy / δ, and HLA-DR. The an�gen-binding protein of any one of item 8 to 31, wherein the cell surface molecule is a TCR / CD3 complex, preferably an alpha / beta TCR / CD3 complex. The an�gen-binding protein of item 32, wherein the an�gen-binding protein comprises: an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein of item 32 or 33, wherein the an�gen-binding protein comprises: a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. The an�gen-binding protein of item 32, wherein the an�gen-binding protein comprises: an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein of item 32 or 35, wherein the an�gen-binding protein comprises: a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. The an�gen-binding protein of any one of items 12 to 36, wherein the TCR an�gen binding site (VR) specifically binds to a bacterial pep�de, a viral pep�de or a tumor associated an�gen pep�de, preferably bound to a major histocompa�bility complex (MHC) protein. A nucleic acid or separate nucleic acids encoding an an�gen-binding protein according to any one of the preceding items. A vector comprising the nucleic acid or the separate nucleic acids or separate vectors comprising the separate nucleic acids according to item 38. A host cell comprising the an�gen-binding protein, the nucleic acid or separate nucleic acids, or the vector or the separate vectors according to any one of the preceding items. A method for producing an an�gen-binding protein, wherein the method comprises (i) cul�va�ng the host cell of item 40, (ii) producing the an�gen-binding protein, and op�onally (iii) harves�ng the host cell, and preferably (iv) isola�ng the an�gen-binding protein. The protein as obtained or obtainable by item 41. A pharmaceu�cal composi�on comprising the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding items or the an�gen binding protein as obtained by item 42. The pharmaceu�cal composi�on, the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding items or the an�gen binding protein as obtained by item 42 for use in medicine. The pharmaceu�cal composi�on, the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, or the host cell according to any one of the preceding items or the an�gen binding protein as obtained by item 42 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. A method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the pharmaceu�cal composi�on, the an�gen- binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding items or the an�gen binding protein as obtained by item 42 to a pa�ent in need thereof. A method of muta�ng an an�gen-binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cystein, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cystein; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cystein, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. A method of increasing the heterodimerisa�on of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. A method of increasing the stability of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. A method of increasing the yield of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. A method of increasing the purity of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. A method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, comprising (i) cul�va�ng the host cell, (ii) producing the an�gen-binding proteins, and op�onally (iii) harves�ng the host cell, and preferably (iv) isola�ng the an�gen-binding proteins, wherein the host cell comprises a nucleic acid encoding afirst an�gen-binding protein comprising at least one heteromeriza�on improving amino acid subs�tu�on and a nucleic acid encoding a second an�gen-binding protein comprising at least one heteromeriza�on improving subs�tu�on. The method of item 52, wherein the heteromeric an�gen-binding proteins are heterodimers and the heteromeriza�on improving amino acid subs�tu�ons are heterodimeriza�on improving amino acid subs�tu�ons. The method of item 53, wherein thefirst an�gen-binding protein is an an�gen-binding protein according to any one of the preceding items. The method of item 54, wherein the heteromeriza�on improving amino acid subs�tu�ons of the second an�gen-binding protein are knob-into-hole amino acid subs�tu�ons or wherein the second an�gen-binding protein is an an�gen-binding protein according to any one of the preceding items. The method of item 55, wherein the second an�gen-binding protein comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid variant T366W and the other polypeptide comprises the amino acid variant T366S, L368A and Y407V. The method of item 56, wherein of the second an�gen-binding protein one polypep�de further comprises the amino acid variant S354C and the other polypeptide further comprises the amino acid variant Y349C. The method of item 57, wherein the second an�gen-binding protein comprises one polypep�de comprising the amino acid sequence according to SEQ ID NO: 17 and another polypeptide comprising the amino acid sequence according to SEQ ID NO: 18. The method of any one of items 52 to 54, wherein the second an�gen-binding protein comprises one polypep�de comprising the sequence according to SEQ ID NO: 19 and another polypeptide comprising the amino acid sequence according to SEQ ID NO: 20. The method of any one of items 52 to 54, wherein the second an�gen-binding protein comprises one polypep�de comprising the sequence according to SEQ ID NO: 21 and another polypeptide comprising the amino acid sequence according to SEQ ID NO: 22. The an�gen-binding proteins as obtained or obtainable by the method of any one of items 52 to 60. A pharmaceu�cal composi�on comprising at least two of the an�gen-binding proteins as defined in any one of the preceding items. A pharmaceu�cal composi�on comprising a nucleic acid or separate nucleic acids encoding at least two of the an�gen-binding proteins as defined in any one of the preceding items. The pharmaceu�cal composi�on of item 62 or 63 for use in medicine. The pharmaceu�cal composi�on of item 64 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. A method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the pharmaceu�cal composi�on of item 62 or 63 to a pa�ent in need thereof. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex(MHC) protein for use as medicine. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. A combina�on comprising an an�gen-binding protein binding to MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen- binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. A pharmaceu�cal composi�on comprising an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. A pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding at least two an�gen- binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on and wherein one of the at least two an�gen- binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen- binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. An an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein. A method of protein produc�on in a cell popula�on, wherein the method comprises contac�ng a cell popula�on with a nucleic acid or nucleic acids encoding at least two an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids under condi�ons such that an effec�ve amount of the protein is produced in the cell popula�on, wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. A method for inducing in vivo transla�on of at least two an�gen-binding proteins in a subject in need thereof, comprising administering to the subject an effec�ve amount of a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids under condi�ons such that the nucleic acid(s) is / are localized into a cell of the subject and the an�gen-binding proteins are capable of being translated in the cell from the nucleic acid(s), wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. A method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 67 to 76, comprising one or more further an�gen- binding proteins. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 67 to 77, wherein the an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and the an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) and op�onally one or more further an�gen-binding proteins act together to provide a desired therapeu�c effect. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 67 to 78, wherein the MAGEA4 / 8 derived pep�de is a pep�de according to SEQ ID NO: 57. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 67 to 79, wherein the PRAME derived pep�de is a pep�de according to SEQ ID NO: 58. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 79 to 80, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 62, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 63, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 64; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 59, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 60, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 61, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen binding proteins for use, the combina�on , the pharmaceu�cal composi�ons or the methods of any one of items 79 to 81, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 54 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 62, 63, and 64, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 53 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 59, 60, and 61, respec�vely. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 79 to 82, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 79 to 83, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 79 to 84, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises or consists of afirst polypep�de chain comprising a structure represented by the formula: VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of item 85, wherein L1 and / or L2 comprise or consist of an amino acid sequence according to SEQ ID NO: 16. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of item 85 or 86, wherein FC1 comprises or consists of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 comprises or consists of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 79 to 87, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 75, 79, 80 or 82 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76, 81 or 83. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 88, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 68, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 69, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 70; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 65, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 66, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 67, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 89, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 56 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 68, 69, and 70, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 55 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 65, 66, and 67, respec�vely. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 90, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 91, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 92, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises or consists of afirst polypep�de chain comprising a structure represented by the formula: VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of item 93, wherein L1 and / or L2 comprise or consist of an amino acid sequence according to SEQ ID NO: 16. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of item 93 or 94, wherein FC1 comprises or consists of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 comprises or consists of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40. 96. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of items 80 to 95, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 71, 74, 84 or 86 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72, 85 or 87. As men�oned above the present inventors iden�fied amino acid subs�tu�ons that improve heterodimeriza�on of heteromeric proteins when combined with subs�tu�ons that introduce a disulphide bridge. In other words, the subs�tu�ons iden�fied by the inventors facilitate the interac�on of subunits of heteromeric proteins when combined with subs�tu�ons that introduce a disulphide bridge. Amino acid subs�tu�ons that improve heterodimeriza�on of heteromeric proteins refer to changes in the amino acid sequence of a polypep�de that enhance its ability to selec�vely pair and form complexes with a specific, non-iden�cal partner polypep�de, while minimizing interac�ons with itself (or other unintended polypep�des). For example, when a protein consists of two non-iden�cal subunits it may be referred to as a heterodimeric protein. In this case it is envisaged in context of the inven�on that one subunit comprises the subs�tu�ons to nega�vely charged amino acids and the other subunit comprises the subs�tu�ons to posi�vely charged amino acids. It is envisaged that due to repulsion of the same charge the interac�on of the iden�cal subunits is reduced. In contrast, due to atrac�on of different charges the interac�on of two of the non-iden�cal subunits is facilitated. It is in par�cular envisaged that the polypep�des that are supposed to interact comprise an�body derived CH3-domains. The CH3-domain is the third constant domain of the heavy chain of an an�body and is located in the Fc region. The CH3 domain contributes to the dimeriza�on of the an�body's heavy chains and provides a structural pla�orm for interac�ons with Fc receptors and complement proteins. This domain plays a cri�cal role in an�body stability and its ability to elicit immune responses. It is envisaged that the described polypep�des are derived from humans. In par�cular it is envisaged that the IgG CH3 domains are human. The present inventors iden�fied amino acid subs�tu�ons in the CH3-domain that improve heterodimeriza�on of heteromeric proteins when combined with subs�tu�ons that introduce a disulphide bridge. The amino acid posi�ons provided herein are posi�ons according to the EU numbering system of an�bodies. Accordingly, the skilled person understands that the disclosed amino acid posi�ons are not necessarily the posi�on in the molecule used but the posi�on the residue would have in an an�body, preferably an IgG an�body, more preferably an IgG1 an�body. For example, when it is referred herein to e.g. a T366K subs�tu�ons, for example in a TCER®, the threonine which has been subs�tuted with lysine is not necessarily at posi�on 366but it refers to the threonine which would be at posi�on 366 in a IgG molecule. The skilled person is readily capable to determine which posi�on the subs�tu�on in the an�gen binding protein actually is. The skilled person may align the CH3-domain of an an�body with the an�gen binding protein sequence and determine the actual posi�on of e.g. threonine 366 of the an�body. Accordingly, it is envisaged that the inven�ve molecule comprises CH3-domains. It is envisaged that the inven�ve molecule comprises CH3-containing polypep�des. “CH3-containing polypep�des” and “CH3-domain-containing polypep�des” are used synonymously herein. In thefirst polypep�de of the molecule or protein of the inven�on the amino acid at posi�on 351 may be subs�tuted by a nega�vely charged amino acid. Also, in thefirst polypep�de the amino acid at posi�on 368 may be subs�tuted by a nega�vely charged amino acid. Furthermore, in the second polypep�de the amino acid at posi�on 351 may be subs�tuted by a posi�vely charged amino acid. In addi�on, in the second polypep�de the amino acid at posi�on 366 may be subs�tuted by a posi�vely charged amino acid. These subs�tu�ons may be combined with the amino acid variant Y349C in thefirst polypep�de and the amino acid variant S354C in the second polypep�de or the amino acid variant S354C in thefirst polypep�de and the amino acid variant Y349C in the second polypep�de. It is envisaged that the cysteine at posi�on 354 in one polypep�de forms a disulphide bridge with the cysteine at posi�on 349 in the other polypep�de. The terms “disulphide bridge”, “cysteine bridge”, “disulphide bond” or “cysteine bond” may be used synonymously herein and refers to a covalent bond formed by two thiol groups. The term “amino acid variant” as used herein may refer to a change in the sequence of amino acids in a protein, resul�ng from a subs�tu�on, inser�on or dele�on. For example, S354C means that the serine at posi�on 354 in the CH3-domain of an an�body is exchanged / replaced by a cysteine. Preferably, the inven�ve molecule is an an�gen-binding protein. “An�gen-binding protein” as used herein refers to a protein that specifically recognizes an an�gen through its an�gen- binding site(s). The term "an�gen" or "target an�gen" as used herein refers to a molecule or a por�on of a molecule or complex that is capable of being bound by at least one an�gen binding site of e.g. an an�gen-binding protein. The terms "an�gen" and “epitope” may be used interchangeably herein. However, “epitope” may also refer to a specific molecular structure on the an�gen. The an�gen or epitope is bound by the an�gen-binding site or an�gen-binding domain. Accordingly, the term “an�gen-binding site” or “an�gen-binding domain” as used herein refers to the structure in the an�gen-binding protein that interacts with the an�gen or epitope e.g. via hydrogen bonds, electrosta�c interac�ons and hydrophobic interac�ons. The phrases “the an�gen-binding protein specifically recognizes”, “the an�gen-binding protein is reac�ve with”, “the an�gen-binding protein binds” or “the an�gen-binding protein specifically binds” may be used synonymously herein and refers to the ability of a protein to bind to another molecule, typically another protein / pep�de, a specific region on a protein / pep�de, a protein / protein complex or a protein / pep�de complex, with high affinity and specificity. This recogni�on may occur through complementary molecular surfaces or structures, where specific interac�ons take place, such as hydrogen bonds, electrosta�c interac�ons and hydrophobic interac�ons. Affinity refers to the strength of the interac�on between two molecules. In the context of proteins, it typically describes how�ghtly a protein binds to another molecule, such as an an�gen. Higher affinity implies a stronger binding interac�on, while lower affinity suggests a weaker binding. Affinity is o�en quan�fied by the dissocia�on constant (Kd). Lower Kd values indicate higher affinity. Specificity refers to the selec�vity of a molecular interac�on, par�cularly the ability of a molecule (such as a protein) to discriminate between different ligands or binding partners. Thus, in the context of proteins, specificity may relate to the ability of a protein to bind selec�vely to its cognate ligand or binding partner, despite the high concentra�on of other molecules present in the corresponding environment. It is evident for the skilled person that in context of the present inven�on specificity may mean the ability of an an�gen-binding protein to discriminate between different an�gens and to bind selec�vely to its target an�gen. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C. The inven�on also relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. In par�cular it is envisaged in context of the inven�on that in thefirst polypep�de of the protein the amino acid at posi�on 351 is subs�tuted by a aspar�c acid or glutamic acid. Also, in thefirst polypep�de the amino acid at posi�on 368 may be subs�tuted by aspar�c acid or glutamic acid. Furthermore, in the second polypep�de the amino acid at posi�on 351 may be subs�tuted by lysine, arginine or his�dine. In addi�on, in the second polypep�de the amino acid at posi�on 366 may be subs�tuted by lysine, arginine or his�dine. These subs�tu�ons may be combined with the amino acid variant Y349C in thefirst polypep�de and the amino acid variant S354C in the second polypep�de or the amino acid variant S354C in thefirst polypep�de and the amino acid variant Y349C in the second polypep�de. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and amino acid variant S354C. Addi�onally, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and amino acid variant Y349C. In par�cular it is envisaged in context of the inven�on that in thefirst polypep�de of the protein the amino acid at posi�on 351 is subs�tuted by a aspar�c acid. Also, in thefirst polypep�de the amino acid at posi�on 368 may be subs�tuted by glutamic acid. Furthermore, in the second polypep�de the amino acid at posi�on 351 may be subs�tuted by lysine. In addi�on, in the second polypep�de the amino acid at posi�on 366 may be subs�tuted by lysine. These subs�tu�ons may be combined with the amino acid variant Y349C in thefirst polypep�de and the amino acid variant S354C in the second polypep�de or the amino acid variant S354C in thefirst polypep�de and the amino acid variant Y349C in the second polypep�de. Accordingly, in a preferred embodiment the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C. In another preferred embodiment the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant Y349C. Again it is pointed out that it is evident for the skilled person that the amino acid posi�ons provided above are not necessarily the posi�ons in the described protein but refer to the corresponding posi�on in a wildtype IgG an�body. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein the CH3 domain of thefirst polypep�de has aspar�c acid at the posi�on corresponding to posi�on 351 in an IgG an�body, glutamic acid at the posi�on corresponding to posi�on 368 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 349 in an IgG an�body; and the CH3 domain of the second polypep�de has lysine at the posi�on corresponding to posi�on 351 in an IgG an�body, lysine at the posi�on corresponding to posi�on 366 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 354 in an IgG an�body. In addi�on, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein the CH3 domain of thefirst polypep�de has aspar�c acid at the posi�on corresponding to posi�on 351 in an IgG an�body, glutamic acid at the posi�on corresponding to posi�on 368 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 354 in an IgG an�body; and the CH3 domain of the second polypep�de has lysine at the posi�on corresponding to posi�on 351 in an IgG an�body, lysine at the posi�on corresponding to posi�on 366 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 349 in an IgG an�body. It is envisaged that thefirst and the second polypep�de of the described an�gen-binding proteins specifically bind to each other, preferably (inter alia) via their CH3-domains. Accordingly, the inven�on relates to an�gen-binding proteins comprising two IgG CH3- containing polypep�des as described herein, wherein thefirst and second polypep�de specifically bind to each other. As men�oned above it is envisaged that the subs�tuted amino acids facilitate the interac�on of the polypep�des or in other words facilitate the binding of the polypep�des to each other e.g. by electrosta�c atrac�on. Without necessarily bound by scien�fic theory, it is envisaged that aspar�c acid at posi�on 351 and glutamic acid at posi�on 368 form electrosta�c interac�ons with lysine at posi�ons 351 and 366. In par�cular, it is envisaged that aspar�c acid at posi�on 351 and glutamic acid at posi�on 368 form electrosta�c interac�ons with lysine at posi�ons 366. Accordingly, the inven�on relates to the herein described proteins, wherein the amino acids subs�tuted in thefirst polypep�de interact with the subs�tuted amino acids in the second polypep�de. It is envisaged that the an�gen-binding proteins in context of the inven�on have more than one an�gen-binding site. In other words, the an�gen-binding protein in context of the inven�on may be a bispecific, trispecific or mul�specific an�gen-binding protein, preferably a bispecific an�gen-binding protein. Accordingly, the inven�on relates to the herein described proteins, wherein the an�gen-binding protein is a bispecific, trispecific or mul�specific an�gen-binding protein, preferably a bispecific an�gen-binding protein. The term “bispecific” in connec�on with the herein described an�gen-binding proteins refers to an�gen-binding proteins with at least two valences and binding specifici�es for two different an�gens and, thus, comprise at least two an�gen-binding sites. The term “valence” refers to the number of binding sites of an an�gen-binding protein, e.g. a bivalent an�gen- binding protein relates to an an�gen-binding protein that has two binding sites. It should be noted, that, the term valence refers to the number of binding sites, wherein those binding sites may bind to the same or different targets, i.e. a bivalent an�gen binding protein may be monospecific, i.e. binding one target, or bispecific, i.e. binding two different targets. Targets may be an�gens, such as (target) pep�des. In the context of “bispecific” it is preferred herein that at least one specificity of the an�gen binding sites is derived from a TCR, more par�cularly, that at least one an�gen-binding site comprises the TCR derived CDRs as described herein. It may also refer that the at least two binding sites are derived from an�bodies. In par�cular, the term “bispecific” in the context of the present inven�on may refer to an an�gen-binding protein which combines at least one an�gen-binding site comprising TCR derived CDRs, and at least one further an�gen-binding site, wherein said at least one further an�gen-binding site, may be derived from an an�body and thus comprises an�body CDRs, or from a further TCR and thus comprises the CDRs of a further TCR, preferably said further an�gen binding site, is derived from an an�body and thus comprises an�body CDRs. As men�oned before, a preferred format is the TCER® format. However, it is envisaged that the herein provided modified CH3 domains may be comprised in any other an�gen binding protein. When it is referred to a bispecific molecule it is, however, possible that e.g. the Fc part of said molecule has an addi�onal binding partner e.g. FcRn. Thus, the the an�gen-binding proteins in context of the inven�on may have afirst binding domain / site and a second binding domain / site. Accordingly, the inven�on relates to the herein described proteins, wherein the an�gen-binding protein comprises afirst binding domain / site and a second binding domain / site. “Binding domain / site” and “an�gen-binding domain / site” may be used interchangeably herein. It is envisaged that one an�gen binding domain binds to a cell surface molecule of a human immune cell. It is envisaged that said surface molecule is known to induce the ac�va�on of the immune cell, or is at least one selected from the group consis�ng of immune response-related molecules, CD3, such as the CD3γ, CD3δ, and CD3ε chains, CD4, CD7, CD8, CD10, CD11b, CD11c, CD14, CD16, CD18, CD22, CD25, CD28, CD32a, CD32b, CD33, CD41 , CD41b, CD42a, CD42b, CD44, CD45RA, CD49, CD55, CD56, CD61, CD64, CD68, CD94, CD90, CD117, CD123, CD125, CD134, CD137, CD152, CD163, CD193, CD203c, CD235a, CD278, CD279, CD287, Nkp46, NKG2D, GITR, FcεRI, TCRa / β, TCRy / δ, and HLA-DR. In particular, the cell surface molecule may be a TCR / CD3 complex, preferably an alpha / beta TCR / CD3 complex. Said an�gen binding site may be an�body derived. Accordingly, a VH and VL may form an an�gen-binding domain that specifically binds to a T cell receptor complex. Binding of the an�gen-binding domain that specifically binds to a T cell receptor complex may ac�vate the T cell. Corresponding variable domains and CDRs are described throughout this applica�on. The domain may bind to any part or epitope of the alpha / beta TCR / CD3 complex. It is also envisaged that one binding domain specifically binds to an MHC-associated pep�de or MHC-associated pep�de epitope. MHC proteins are a set of cell surface proteins essen�al for the acquired immune system to recognize foreign molecules in vertebrates, which inter alia determines histocompa�bility. The main func�on of MHC molecules is to bind to an�gens derived from pathogens and tumor an�gens and display them on the cell surface for recogni�on by the appropriate T cells. It is preferred that the MHC protein belongs to MHC class I. It is further preferred that the MHC protein is of the serotype group HLA-A, preferably HLA-A*24 or HLA-A*02. It is most preferred that the MHC protein is of the serotype HLA-A*02. The skilled person is well aware that HLA-A*02 can be further subdivided. A preferred serotype is HLA-A*02:01. The skilled person understands that when it is referred herein to HLA-A*02 the serotype HLA-A*02:01 is preferred. As described further herein it is in par�cular envisaged that the an�gen-binding domain binding to an MHC-associated pep�de comprises or consists of a T cell receptor (TCR) or a func�onal fragment or deriva�ve thereof. Accordingly, it is envisaged that the herein described an�gen-binding proteins comprises afirst binding domain specifically binding to a cell surface molecule of a human immune cell and / or a second binding domain specifically binding to an MHC-associated pep�de epitope. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and amino acid variant Y349C; and wherein the an�gen-binding protein comprises afirst binding domain specifically binding to a cell surface molecule of a human immune cell and a second binding domain specifically binding to an MHC-associated pep�de epitope. Furthermore, it is envisaged that in the herein described an�gen-binding proteins thefirst and / or second binding domain comprises or consists of an an�body or a func�onal fragment or deriva�ve thereof. In an “an�body” also called “immunoglobulin“ two heavy chains are linked to each other by disulfide bonds and each heavy chain is linked to a light chain by a disulfide bond. There are two types of light chain, lambda (l) and kappa (k). There arefive main heavy chain classes (or isotypes) which determine the func�onal ac�vity of an an�body molecule: IgM, IgD, IgG, IgA and IgE. Each chain contains dis�nct sequence domains. The light chain includes two domains or regions, a variable domain (VL) and a constant domain (CL). The heavy chain includes four domains, a variable domain (VH) and three constant domains (CH1, CH2 and CH3, collec�vely referred to as CH or Fc or Fc domain). The variable regions of both light (VL) and heavy (VH) chains determine binding recogni�on and specificity to the an�gen. The constant region domains of the light (CL) and heavy (CH) chains confer important biological proper�es such as an�body chain associa�on, secre�on, trans-placental mobility, complement binding and binding to Fc receptors (FcR). The Fv fragment is the N-terminal part of the Fab fragment of an immunoglobulin and consists of the variable por�ons of one light chain and one heavy chain. The specificity of the an�body resides in the structural complementarity between the an�body combining site (synonym to an�body binding site) and the an�genic determinant. An�body combining sites are made up of residues that are primarily from the hypervariable or complementarity determining regions (CDRs). CDRs refer to amino acid sequences that together define the binding affinity and specificity of the natural Fv region of a na�ve immunoglobulin binding site. The light and heavy chains of an immunoglobulin each have three CDRs, that may be referred to as CDR1-L, CDR2-L, CDR3-L and CDR1-H, CDR2-H, CDR3-H, respec�vely or CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3, respec�vely. A conven�onal an�body an�gen binding site, therefore, includes six CDRs, comprising the CDR set from each of a heavy and a light chain V region. In the context of the applica�on, an an�body may be an IgM, IgD, IgG, IgA or IgE. “An�body Framework Regions” (FRs) refer to amino acid sequences interposed between CDRs, i.e. to those por�ons of immunoglobulin light and heavy chain variable regions that are rela�vely conserved among different immunoglobulins in a single species. The light and heavy chains of an immunoglobulin each have four FRs, designated FR1-L, FR2-L, FR3-L, FR4-L, and FR1-H, FR2-H, FR3-H, FR4-H, respec�vely. Accordingly, the light chain variable domain may thus be designated as (FR1-L)-(CDR1-L)-(FR2-L)-(CDR2-L)-(FR3-L)-(CDR3-L)-(FR4-L) and the heavy chain variable domain may thus be designated as (FR1-H)-(CDR1-H)-(FR2-H)-(CDR2-H)- (FR3-H)-(CDR3-H)-(FR4-H). CDR / FR defini�on in an immunoglobulin light or heavy chain, may be determined based on IMGT defini�on (Lefranc et al. Dev. Comp. Immunol., 2003, 27(1):55-77; www.imgt.org). In context of the present applica�on it is preferred that CDR / FR defini�on in an immunoglobulin light or heavy chain are determined according to Kabat numbering (Kabat et al., 1992, Sequences of Proteins of Immunological Interest). Accordingly, amino acid sequences of the CDR1, CDR2 and CDR3 of a given variable chain of an an�body or an�body fragment are indicated according to said Kabat defini�on. Knowing the amino acid sequence of the CDRs of an an�body, a TCR or an an�gen binding protein of the inven�on, one skilled in the art can easily determine the framework regions, such as the TCR framework regions or an�body framework regions. However, in cases where the CDRs are not indicated, the person skilled in the art canfirst determine the CDR amino acid sequences based on the IMGT defini�on for TCRs or the IMGT defini�on or Kabat defini�on for an�bodies and then determine the amino acid sequences of the framework regions. As used herein, a "human framework region" is a framework region that is substan�ally iden�cal (about 85%, or more, in par�cular 90%, 95%, 97%, 99% or 100%) to the framework region of a naturally occurring an�gen-binding protein, such as a naturally occurring human an�body or human TCR. A func�onal fragment or deriva�ve of an an�body refers to a modified form of the an�body molecule that retains some or all of its func�onal proper�es but may have altered characteris�cs such as size or structure. These modifica�ons can be made to enhance the an�body's therapeu�c poten�al, improve its stability, reduce immunogenicity or enable specific interac�ons with target molecules. Fragments of an�bodies may comprise a por�on of an intact an�body, in par�cular the an�gen-binding region or variable region of the intact an�body. Examples of an�body fragments include Fv, Fab, F(ab')2, Fab', dsFv, (dsFv)2, scFv and sc(Fv)2. A fragment of an an�body may also be a single domain an�body, such as a heavy chain an�body (including nanobodies) or VHH. Furthermore, it is envisaged that in the herein described an�gen-binding proteins thefirst and / or second binding domain comprises or consists of a T cell receptor (TCR) or a func�onal fragment or deriva�ve thereof. A TCR is a heterodimeric cell surface protein of the immunoglobulin super-family, which is associated with invariant proteins of the CD3 complex involved in mediating signal transduction. TCRs exist in αβ and γδ forms, which are structurally similar but have quite distinct anatomical locations and probably functions. The extracellular portion of native heterodimeric αβ TCR and γδ TCR each contain two polypeptides, each of which has a membrane-proximal constant domain and a membrane-distal variable domain. Each of the constant and variable domains include an intra-chain disulfide bond. The variable domains contain the highly polymorphic loops analogous to the complementarity determining regions (CDRs) of antibodies. The term TCR herein denotes TCRs and fragments thereof, as well as single chain TCRs and fragments thereof, in particular variable alpha and beta domains of single domain TCRs, and chimeric, humanized, bispecific or multispecific TCRs. Fragments of a TCR comprise a por�on of an intact or na�ve TCR, in par�cular the an�gen- binding region or variable region of the intact or na�ve TCR. Examples of TCR fragments include fragments of the α, β, δ, γ chain, such as Vα- Caor Vβ- Cβor por�ons thereof, such fragments might also further comprise the corresponding hinge region or single variable domains, such as Vα, Vβ, Vδ, Vγ, or single chain VαVβ fragments. Fragments of a TCR may exert iden�cal func�ons compared to the naturally occuring full-length TCR, i.e. fragments selec�vely and specifically bind to their target pep�de. The TCR may also be a single chain TCR (scTCR). scTCR herein denotes a protein wherein the variable domains of the TCR, such as the Vαand Vβor Vδand Vγare located on one polypeptide. Typically, the variable domains are separated by a linker, wherein said linker typically comprises 5 to 20, such as 5 to 15 amino acids. “Na�ve” as used for example in the wording “na�ve TCR” refers to a wildtype TCR. Na�ve alpha-beta heterodimeric TCRs have an alpha chain and a beta chain. The skilled person is well aware how the TCR chains are assembled by recombina�on of the corresponding genomic regions (Lefranc, (2001), Curr Protoc Immunol Appendix 1: Appendix 10; Folch and Lefranc, (2000), Exp Clin Immunogenet 17(1): 42-54; Scaviner and Lefranc, (2000), Exp Clin Immunogenet 17(2): 83-96; LeFranc and LeFranc, (2001), "T cell Receptor Factsbook", Academic Press). For more informa�on on immunoglobulin an�body and TCR genes see the interna�onal ImMunoGeneTics informa�on system®, Lefranc M-P et al (Nucleic Acids Res. 2015 Jan; 43 (Database issue):D413-22; and htp: / / www.imgt.org / ). Each variable region, herein referred to as alpha variable domain and beta variable domain, comprises three Complementarity Determining Regions (CDRs) embedded in a framework sequence, one being the hypervariable region named CDR3. The alpha variable domain CDRs may be referred to as CDRa1, CDRa2 and CDRa3 or CDRα1, CDRα2, and CDRα3 and the beta variable domain CDRs may herein referred to as CDRb1, CDRb2 and CDRb3 or CDRβ1, CDRβ2, and CDRβ3. A conven�onal TCR an�gen binding site, therefore, includes, usually, six CDRs, comprising the CDR set from each of an alpha and a beta chain variable region, wherein CDR1 and CDR3 sequences are relevant for the recogni�on and binding of the pep�de an�gen that is bound to the HLA protein and the CDR2 sequences are relevant for the recogni�on and binding of the HLA protein. Analogous to an�bodies, TCR framework regions (FRs) refer to amino acid sequences interposed between CDRs, i.e. to those por�ons of TCR alpha and beta chain variable regions that are to some extent conserved among different TCRs in a single species. The alpha and beta chains of a TCR each have four FRs, herein designated FR1-a, FR2-a, FR3-a, FR4-a, and FR1-b, FR2-b, FR3-b, FR4-b, respec�vely. Accordingly, the alpha chain variable domain may thus be designated as (FR1-a)-(CDRa1)-(FR2-a)-(CDRa2)-(FR3-a)-(CDRa3)-(FR4-a) and the beta chain variable domain may thus be designated as (FR1-b)-(CDRb1)-(FR2-b)-(CDRb2)-(FR3-b)- (CDRb3)-(FR4-b). In the context of the inven�on, CDR / FR defini�on in an α or β chain is to be determined based on IMGT defini�on (Lefranc et al. Dev. Comp. Immunol., 2003, 27(1):55-77; www.imgt.org). Similarly, na�ve gamma-delta heterodimeric TCRs have a gamma chain and a delta chain. The skilled person is well aware how the TCR chains are assembled by recombina�on of the corresponding genomic regions (Lefranc, (2001), Curr Protoc Immunol Appendix 1: Appendix 10; Folch and Lefranc, (2000), Exp Clin Immunogenet 17(1): 42-54; Scaviner and Lefranc, (2000), Exp Clin Immunogenet 17(2): 83-96; LeFranc and LeFranc, (2001), "T cell Receptor Factsbook", Academic Press). For more informa�on on immunoglobulin an�body and TCR genes see the interna�onal ImMunoGeneTics informa�on system®, Lefranc M-P et al (Nucleic Acids Res.2015 Jan; 43 (Database issue):D413-22; and htp: / / www.imgt.org / ). Also, CDR / FR defini�on in an γ or δ chain is to be determined based on IMGT defini�on (Lefranc et al. Dev. Comp. Immunol., 2003, 27(1):55-77; www.imgt.org). Accordingly, CDR / FR amino acid posi�ons when related to TCR or TCR derived domains are indicated according to said IMGT defini�on. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and wherein the an�gen-binding protein comprises afirst binding domain comprising or consis�ng of an an�body or a func�onal fragment or deriva�ve thereof and a second binding domain comprising or consis�ng of a T cell receptor (TCR) or a func�onal fragment or deriva�ve thereof. In the herein described an�gen-binding proteins, thefirst binding domain may comprise or consist of an an�body an�gen binding site (or a TCR an�gen binding site) (VD). It is envisaged that one part of the an�body an�gen binding site (VD) is on one CH3-containing polypep�de and the other part of the an�body an�gen binding site (VD) is on the other CH3-containing polypep�de. Accordingly, in specific embodiments, the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein one polypep�de comprises the an�body variable light chain domain (VL) of an an�gen binding site (VD) and the other polypep�de comprises the an�body variable heavy chain domain (VH) of an an�gen binding site (VD). Although evident for the skilled person it is pointed out that it is envisaged that the an�body variable light chain domain (VL) and the an�body variable heavy chain domain (VH) associate to form a func�onal an�body an�gen-binding site (VD). Accordingly, in certain embodiments, the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein one polypep�de comprises the an�body variable light chain domain (VL) of an an�gen-binding site (VD) and the other polypep�de comprises the an�body variable heavy chain domain (VH) of an an�gen-binding site (VD), wherein the an�body variable light chain domain (VL) and the an�body variable heavy chain domain (VH) associate to form a func�onal an�body an�gen-binding site (VD). It is further envisaged that in the herein described an�gen-binding proteins the second binding domain may comprise or consist of a TCR an�gen binding site (VR). In further certain embodiments, thefirst and the second binding domain may be derived from an�bodies, and may comprise fragments of an�bodies, e.g. variable domains of an�bodies. One part of the TCR an�gen binding site (VR) may be on one CH3-containing polypep�de and the other part of the TCR an�gen binding site (VR) may be on the other CH3-containing polypep�de. Accordingly, in such embodiments, the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein one polypep�de comprises the TCR alpha variable domain (Vα) of a TCR an�gen-binding site (VR) and the other polypep�de comprises the TCR beta variable domain (Vβ) of a TCR an�gen-binding site (VR). Although evident for the skilled person it is pointed out that it is envisaged that TCR alpha variable domain (Vα) and the TCR beta variable domain (Vβ) associate to form a func�onal TCR an�gen binding site (VR). Accordingly, in par�cular embodiments, the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein one polypep�de comprises the TCR alpha variable domain (Vα) of a TCR an�gen-binding site (VR) and the other polypep�de comprises the TCR beta variable domain (Vβ) of a TCR an�gen-binding site (VR), wherein the TCR alpha variable domain (Vα) and the TCR beta variable domain (Vβ) associate to form a func�onal TCR an�gen binding site (VR). Specifically, the inven�on relates to an an�gen-binding protein comprising two of the herein described IgG CH3-containing polypep�des, wherein one polypep�de comprises an an�body variable light chain domain (VL) and a TCR beta variable domain (Vβ) and the other polypep�de comprises an an�body variable heavy chain domain (VH) and a TCR alpha variable domain (Vα). Furthermore, the inven�on relates to an an�gen-binding protein comprising two of the described IgG CH3-containing polypep�des, wherein one polypep�de comprises an an�body variable light chain domain (VL) and a TCR alpha variable domain (Vα) and the other polypep�de comprises an an�body variable heavy chain domain (VH) and a TCR beta variable domain (Vβ). The herein described an�gen-binding proteins may comprise further an�body-derived domains. In par�cular, it is envisaged that the herein described an�gen-binding proteins further comprise a CH2 domain. The CH2-domain is the second constant domain of the heavy chain of an an�body and is located in the Fc region. The inven�on relates to an an�gen-binding protein comprising two (of the described) IgG CH3-containing polypep�des, wherein thefirst polypep�de further comprises a CH2 domain and / or the second polypep�de further comprises a CH2 domain. It is envisaged that in the herein described an�gen-binding proteins a CH2 domain and a CH3 domain form a Fc domain. Accordingly, in one polypep�de the CH2 domain and the CH3 domain may form a Fc domain FC1 and / or in the other polypep�de the CH2 domain and the CH3 domain may form a Fc domain FC2. Thus, the inven�on relates to an an�gen-binding protein comprising two of the herein described IgG CH3-containing polypep�des, wherein in one polypep�de the CH2 domain and the CH3 domain form a Fc domain FC1 and / or in the other polypep�de the CH2 domain and the CH3 domain form a Fc domain FC2. The term "Fc domain" as used in the context of the present invention encompasses native Fc domains and Fc domain variants and sequences as further defined herein below. As with Fc variants and native Fc molecules, the term "Fc domain" includes molecules in monomeric or multimeric form, whether digested from whole antibody or produced by other means. The term "native Fc" as used herein refers to a molecule comprising the sequence of a non- antigen-binding fragment resulting from digestion of an antibody or produced by other means, whether in monomeric or multimeric form, and may contain the hinge region. The original immunoglobulin source of the native Fc is, in particular, of human origin and can be any of the immunoglobulins, preferably lgG1 or lgG2, most preferably lgG1. Native Fc molecules are made up of monomeric polypeptides that can be linked into dimeric or multimeric forms by covalent (i.e., disulfide bonds) and non-covalent association. The number of intermolecular disulfide bonds between monomeric subunits of native Fc molecules ranges from 1 to 4 depending on class (e.g., IgG, IgA, and IgE) or subclass (e.g., lgG1, lgG2, lgG3, IgA1, and lgA2). One example of a native Fc is a disulfide-bonded dimer resulting from papain digestion of an IgG. The term "native Fc" as used herein is generic to the monomeric, dimeric, and multimeric forms. The "hinge" or "hinge region" or "hinge domain" refers typically to the flexible portion of a heavy chain located between the CH1 domain and the CH2 domain. It is approximately 25 amino acids long, and is divided into an "upper hinge," a "middle hinge" or "core hinge," and a "lower hinge." A "hinge subdomain" refers to the upper hinge, middle (or core) hinge or the lower hinge. The skilled person understands at least when looking at the sequences described herein that FC1 and / or FC2 may comprise a hinge region, in particular the hinge region according to SEQ ID NO: 15 (EPKSS). Accordingly, FC1 and / or FC2 may be formed by a Fc domain and a hinge region, preferably wherein the hinge region comprises or consists of SEQ ID NO: 15 (EPKSS). Accordingly, in certain embodiments, the inven�on relates to the herein described an�gen- binding proteins, wherein FC1 and / or FC2 further comprise a hinge region, preferably wherein the hinge region comprises or consists of SEQ ID NO: 15 (EPKSS). When it is referred herein to amino acid positions in the Fc domain, these amino acid positions or residues are indicated according to the EU numbering system as described, for example in Edelman et al., Proc. Natl. Acad. USA, 1969, 63, 78-85. The term "Fc variant" or “Fc domain variant” as used herein refers to a molecule or sequence that is modified from a native Fc but still comprises e.g. a binding site for the salvage receptor, FcRn (neonatal Fc receptor). Exemplary Fc variants, and their interaction with the salvage receptor, are known in the art. Thus, the term "Fc variant" can comprise a molecule or sequence that is humanized from a non-human native Fc. Furthermore, a native Fc comprises regions that can be removed because they provide structural features or biological activity that are not required for e.g. the bispecific antigen-binding proteins described herein. Thus, the term "Fc variant" comprises a molecule or sequence that lacks one or more native Fc sites or residues, or in which one or more Fc sites or residues have been modified, that affect or are involved in: (1) disulfide bond formation, (2) incompatibility with a selected host cell, (3) N-terminal heterogeneity upon expression in a selected host cell, (4) glycosylation, (5) interaction with complement, (6) binding to an Fc receptor other than a salvage receptor, or (7) antibody-dependent cellular cytotoxicity (ADCC). In particular, when the bispecific antigen-binding protein comprises two Fc domains, i.e. in the TCER® format described herein (such as FC1 and FC2), the two Fc domains may be of the same immunoglobulin isotype or isotype subclass or of different immunoglobulin isotypes or isotype subclasses, preferably of the same. Accordingly, FC1 and FC2, may be of the IgG1 subclass, or of the lgG2 subclass, or of the lgG3 subclass, or of the lgG4 subclass, preferably of the lgG1 subclass, or of the lgG2 subclass, more preferably of the lgG1 subclass. The Fc domain may be a Fc domain variant and thus comprises one or more of the amino acid substitutions described herein below. The Fc domain may comprises or further comprise the “RF” mutation. The “RF mutation“ typically refers to the amino acid substitutions of the amino acids HY into RF in the CH3 domain of Fc domains, such as the amino acid substitution H435R and Y436F in CH3 domain as described by Jendeberg et al. (Jendeberg et al., J. Immunological Meth., 1997, 201: 25-34) and is described as advantageous for purification purposes as it abolishes binding to protein A. In case the bispecific antigen binding protein comprises two Fc domains, the RF mutation may be in one or both, preferably in one Fc domain. The Fc domain on one or both, preferably both polypeptide chains of the antigen-binding protein may comprise one or more alterations that inhibit Fc gamma receptor (FcyR) binding. Such alterations may include L234A or L235A. With the inclusion of Fc-parts consisting of Hinges, CH2 and CH3 domains, or parts thereof, into antigen-binding proteins, more particularly into bispecific antigen-binding proteins the problem of unspecific immobilization of these molecules, induced by Fc:Fc-gamma receptor (FcgR) interactions may arise. FcgRs are composed of different cell surface molecules (FcgRI, FcgRIla, FcgRIlb, FcgRI 11) binding with differing affinities to epitopes displayed by Fc-parts of IgG-molecules. As such an unspecific (i.e. not induced by either of the two binding domains of a bispecific molecule) immobilization is unfavorable due to i) influence on pharmacokinetics of a molecule and ii) off-target activation of immune effector cells various Fc-variants and mutations to ablate FcgR-binding have been identified. In this context, Morgan et al. disclose the exchange of the residues 233-236 of human lgG1 with the corresponding sequence derived from human lgG2, i.e. the residues 233P, 234V and 235A and wherein no amino acid is present at position 236, resulting in abolished FcgRI binding, abolished C1q binding and diminished FcgRIII binding (Morgan et al., Immunology., 1995, 86(2): 319–324). EP1075496 discloses antibodies and other Fc-containing molecules with variations in the Fc region (such as one or more of 233P, 234V, 235A and no residue or G in position 236 and 327G, 330S and 331S) wherein the recombinant antibody is capable of binding the target molecule without triggering significant complement-dependent lysis or cell mediated destruction of the target. Accordingly, the Fc region may comprise or further comprise one or more of the amino acids or deletions selected from the group consisting of 233P, 234V, 235A, 236 (No residue) or G, 327G, 330S, 331S, preferably, the Fc region comprises or further comprises the amino acids 233P, 234V, 235A, 236 (No residue) or G and one or more amino acids selected from the group consisting of 327G, 330S, 331S, most preferably, the Fc region comprises or further comprises the amino acids 233P, 234V, 235A, 236 (No residue) and 331S. It is also envisaged that FC1 and / or FC2 comprises at least one effector func�on silencing muta�on / subs�tu�on at a residue selected from posi�ons 233, 234, 235, 236, 297 and 331, preferably wherein said effector func�on silencing muta�on / subs�tu�on is generated by replacing / subs�tu�ng at least one residue in posi�on 233, 234, 235, 236, and 331 with the corresponding residue derived from lgG2 or lgG4. The Fc domain may comprise or further comprise the amino acid substitution N297Q, N297G or N297A, preferably N297Q. The amino acid substitution “N297Q”, “N297G” or “N297A” refer to amino acid substitutions at position 297 that abrogate the native N-Glycosylation site within the Fc-domain. This amino acid substitution prevents Fc-gamma-receptor interaction and decreases the variability of the final protein products, i.e. the bispecific antigen-binding proteins described herein, due to sugar residues as described for example in Tao and Morrison (Tao and Morrison, J Immunol., 1989, 143(8):2595-601). The described antigen binding proteins may further comprise L242C and K334C located in the same Fc-domain, either in the FC1 or FC2 of one or both polypeptides to form a intradomain C-C bridge. The skilled person is readily capable to determine whether the above described mutations / substitutions are present in the disclosed sequences. Accordingly, the skilled person knows that when it is referred herein to antigen-binding proteins via sequence identity to disclosed sequences said mutations / substitutions may need to be present in said antigen- binding proteins. In particular, it is evident for the skilled person that when it is referred herein to the described FC1 and / or FC2 via sequence identity the described substitutions improving heteromerization need to be present. In the herein described an�gen-binding proteins comprising at least two polypep�de chains the polypep�de chains may be connected by a linker. Accordingly, the inven�on may relate to an an�gen-binding protein comprising two of the herein described IgG CH3-containing polypep�des, wherein thefirst polypep�de and the second polypep�de are on separate polypep�de chains or are connected by a linker. As men�oned above, the herein described an�gen-binding domains may comprise an an�gen- binding site derived from an an�body, wherein the an�body variable light chain domain (VL) and the an�body variable heavy chain domain (VH) are on different polypep�de chains and an an�gen-binding site derived from a TCR, wherein TCR alpha variable domain (Vα) and the TCR beta variable domain (Vβ) are on different polypep�de chains. Accordingly, the inven�on may relate to the herein described an�gen-binding proteins, wherein thefirst polypep�de comprises a structure represented by the formula: V1-V2 [I]; and the second polypep�de comprises a structure represented by the formula: V3-V4 [II]; wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. Accordingly, the inven�on relates to an an�gen-binding protein comprising two IgG CH3- containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; wherein thefirst polypep�de comprises a structure represented by the formula: V1-V2 [I]; and the second polypep�de comprises a structure represented by the formula: V3-V4 [II]; wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. It is envisaged that in the herein described an�gen-binding proteins the variable domains are connected by linkers. Accordingly, the inven�on may relate to the herein described an�gen-binding proteins, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2 [III]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4 [IV]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2 [III]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4 [IV]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. As men�oned above, it is envisaged that the described an�gen-binding proteins comprise FC1 and / or FC2. Accorddingly, the inven�on relates to the herein described an�gen-binding proteins, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 [V]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 [VI]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. Such an an�gen binding protein is herein referred to as a TCER. It is further envisaged that the herein described beneficial CH3 domains can be comprised in or added to any other an�gen binding protein, e.g. as single chain or Tandem diabodies, VHHs, ImmTACs, An�calins, Nanobodies, BiTE®, a Fab, ankyrin repeat proteins or DARPINs, Avimers, a DART, other TCR-like an�bodies, Adnec�ns, Affilins, Trans-bodies, Affibodies, a TrimerX, MicroProteins, Fynomers, Centyrins or a KALBITOR®. The inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 [V]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 [VI]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. It is envisaged that also the variable domains and FC1 and / or FC2 are connected by linkers. Accordingly, the inven�on relates to the herein described an�gen-binding proteins, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-L3-FC1 [VII]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-L4-FC2 [VIII]; wherein L1, L2, L3 and L4 are linkers and may be the same or different, and wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-L3-FC1 [VII]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-L4-FC2 [VIII]; wherein L1, L2, L3 and L4 are linkers and may be the same or different, and wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL. The skilled person is readily capable to choose suitable linkers. In particular the skilled person is readily capable to choose suitable linkers for L1, L2, L3 and / or L4 used herein. The term "linker" as used herein refers to one or more amino acid residues inserted between domains to provide sufficient mobility for the domains or elements, for example the variable domains of bispecific antigen-binding proteins to fold correctly to form the antigen-binding sites. In some embodiments, a linker consists of 0 amino acids meaning that the linker is absent. A linker, as long as it is not specified otherwise in the respective context, can be from at least 1 to 30 amino acids in length. A linker can be 2-25, 2-20, or 3-18 amino acids long. A linker can be a peptide of a length of no more than 14, 13, 12, 11, 10, 9, 8, 7, 6, or 5 amino acids. A linker can be 5-25, 5-15, 4-11, 10-20, or 20-30 amino acids long. A linker can also be about, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids long, preferably 8 amino acids long. A linker can be less than 24, less than 20, less than 16, is less than 12, less than 10, for example from 5 to 24, 10 to 24 or 5-10 amino acid residues in length. A linker may be equal to 1 or more amino acid residues in length, such as more than 1, more than 2, more than 5, more than 10, more than 20 amino acid residues in length, or more than 22 amino acid residues in length. Preferably, the linker is a glycine / serine linker, i.e. a linker consisting of or essentially consisting of glycine and serine residues. Preferably, the linker comprises or consists of SEQ ID NO: 16 (GGGSGGGG). Accordingly, the invention relates to the herein described antigen-binding proteins, wherein the linkers L1, L2, L3 and / or L4 comprise or consist of SEQ ID NO: 16 (GGGSGGGG). The an�gen-binding proteins may comprise the FC1 and / or FC2 of an�gen-binding proteins as used in the appended examples. In par�cular FC1 may comprise or consist of the amino acid sequence according to SEQ ID NO: 1. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant Y349C. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 and comprise the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C. It is pointed out that when it is referred herein to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1” in par�cular the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 and comprising the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C” is encompassed. FC1 may also comprise or consist of the amino acid sequence according to SEQ ID NO: 39. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant S354C. FC1 may comprise or consist of the amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and comprise the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C. It is pointed out that when it is referred herein to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39” in par�cular the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and comprising the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C” is encompassed. FC2 may comprise or consist of the amino acid sequence according to SEQ ID NO: 2. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and the amino acid variant S354C. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 and comprise the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C. It is pointed out that when it is referred herein to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2” in par�cular the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 and comprising the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C” is encompassed. FC2 may also comprise or consist of the amino acid sequence according to SEQ ID NO: 40. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and amino acid variant Y349C. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40 and comprise the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and amino acid variant Y349C. FC2 may comprise or consist of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40 and comprise the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C. It is pointed out that when it is referred herein to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40” in par�cular the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40 and comprising the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C” is encompassed. Accordingly, the antigen-binding protein according to the invention may comprise FC1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1; and / or FC2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 2 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2. Furthermore, the antigen-binding protein according to the invention may comprise FC1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39; and / or FC2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40. In par�cular, the inven�on relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2. The inven�on also relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40. As mentioned above, it is envisaged that an antigen-binding site / domain of the herein described antigen-binding domains binds to a cell surface molecule of an immune cell. In particular, it is envisaged that an antibody antigen-binding domain binds to a TCR / CD3 complex, preferably an alpha / beta TCR / CD3 complex. Said an�gen-binding domain may also be referred to as T-cell recrui�ng part. It is in par�cular envisaged that said an�gen-binding domain binding to a TCR / CD3 complex is the an�gen-binding domain of the antibody BMA031 (V36) as described in WO2021 / 023657. SEQ ID NO: 42 (VL) of WO2021 / 023657 corresponds to SEQ ID NO: 3 in the present applica�on and SEQ ID NO: 43 (VH) of WO2021 / 023657 corresponds to SEQ ID NO: 9 in the present applica�on. Accordingly, it is envisaged that the herein described an�gen-binding proteins comprise an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The inven�on relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or 39, or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or 40, or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. In par�cular it is envisaged that the T cell recrui�ng domain comprises a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 3 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 3 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; It is evident for the skilled person that under certain condi�ons a glutamine amino acid residue may be converted into pyro-glutamate. In par�cular, N-terminal glutamine may be converted into pyro-glutamate. Accordingly, it is evident for the skilled person that the present applica�on also encompasses the described an�gen-binding proteins with pyro-glutamate at the N-terminus instead of glutamine. In other words, when an an�gen-binding protein as described herein has a glutamine residue at the N-terminus also the corresponding amino acid sequence with pyro-glutamate instead of glutamine at the N-terminus is encompassed. For example, when in the described an�gen-binding protein the VL having the amino acid sequence according to SEQ ID NO: 3 is at the N-terminus said VL may comprise or consist of the amino acid sequence according to SEQ ID NO: 4 (with pyro-glutamate at the N-terminus). Accordingly, the an�gen-binding proteins according to the inven�on may comprise a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 4. The an�gen- binding proteins according to the inven�on may also comprise a VL comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 4. The an�gen-binding proteins according to the inven�on may comprise a VL comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 4 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely. For simplicity it is mostly referred to SEQ ID NO: 5 (encompassing glutamine and pyro-glutamate at the N-terminus) herein in context of the preferred VL. It is evident for the skilled person that SEQ ID NO: 5 and “SEQ ID NO: 3 or SEQ ID NO: 4” may be used interchangeably herein. In other words, when it is referred to SEQ ID NO: 5 it may also be referred to as “SEQ ID NO: 3 and SEQ ID NO: 4” or “SEQ ID NO: 3 or SEQ ID NO: 4”. It is evident for the skilled person that the herein described an�gen-binding proteins may be a mixture of molecules with pyro-glutamate at the N-terminus and molecules with glutamine at the N- terminus. Accordingly, when it is referred herein to an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 it is evident for the skilled person that it may be referred to a composi�on comprising an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 3 and op�onally comprising an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 4. Similarly, when it is referred herein to an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 it is evident for the skilled person that it may be referred to a composi�on comprising an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 4 and op�onally comprising an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 3. When it is referred herein to an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 it is evident for the skilled person that it may be referred to a composi�on comprising an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 3 and op�onally comprising at least 50%, at least 60%, at least 70%, at least 80% or at least 90% of an an�gen-binding protein comprising a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 4. Thus, the described an�gen-binding proteins may comprise a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5. The described an�gen-binding proteins may comprise a VL comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5. The described an�gen-binding proteins may comprise a VL comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely. The described an�gen-binding proteins may comprise a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9. The described an�gen-binding proteins may comprise a VH comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9. The described an�gen-binding proteins may comprise a VH comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. Thus, the inven�on relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des as described, wherein the an�gen-binding protein comprises: a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. The inven�on relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and wherein the VL comprises or consists of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprises the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and the VH comprises or consists of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprises the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. Furthermore, it is envisaged that the an�gen-binding domain binding to a TCR / CD3 complex is the an�gen-binding domain of a version of the antibody BMA031 as described in WO2022 / 233957. SEQ ID NO: 2 (VL) of WO2022 / 233957 corresponds to SEQ ID NO: 3 in the present applica�on and SEQ ID NO: 32 (VH) of WO2022 / 233957 corresponds to SEQ ID NO: 13 in the present applica�on. Accordingly, it is envisaged that the herein described an�gen-binding proteins comprise an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The inven�on relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The T cell recrui�ng domain may also comprise a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13. Accordingly, the described an�gen-binding proteins may comprise a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13. The described an�gen-binding proteins may comprise a VH comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13. The described an�gen-binding proteins may comprise a VH comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. Accordingly, the described an�gen-binding proteins may comprise a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. The inven�on further relates to an an�gen-binding protein, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and the VL comprises or consists of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprises the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and the VH comprises or consists of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprises the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. It is envisaged that the TCR an�gen binding site (VR) of the described an�gen-binding proteins may specifically bind to a bacterial pep�de, a viral pep�de or a tumor associated an�gen pep�de, preferably bound to a major histocompa�bility complex (MHC) protein. Preferably, the TCR an�gen binding site (VR) of the described an�gen-binding proteins may specifically bind to a tumor associated an�gen pep�de, preferably bound to a major histocompa�bility complex (MHC) protein. A preferred tumor associated antigen that is bound by the antigen-binding proteins described herein is the MAGE-A antigenic peptide comprising or consisting of the amino acid sequence “KVLEHVVRV” (SEQ ID NO: 57), more particularly, the MAGE-A antigenic peptide comprising or consisting of the amino acid sequence “KVLEHVVRV” (SEQ ID NO: 57) in a complex with a MHC protein. “MAGE-A” or “melanoma associated an�gen A” subfamily proteins were thefirst tumor associated an�gens iden�fied at the molecular level (van der Bruggen et al., Science. 1991; 254:1643–47). MAGE-A is a sub-family of 12 genes (MAGE-A1 to -A12) located in the q28 region of the X chromosome. Members of the MAGE-A subfamily proteins are normally expressed only in tes�s or placenta and their restricted expression suggests that they may func�on in germ cell development. MAGE-A proteins were also detected in the early development of the central nervous system, the spinal cord and brainstem, revealing that MAGE-A proteins may also be involved in neuronal development. The members of this family encode proteins with 50 to 80% sequence iden�ty to each other and all MAGE proteins share the common MAGE homology domain, a highly conserved domain consis�ng of approximately 170 amino acids. The biological func�ons and underlying regulatory mechanism of MAGE-A proteins expression in cancer is s�ll not fully understood. The “MAGE-A4” or “Melanoma-associated an�gen 4” protein is a member of the MAGE-A gene family and has the Uniprot accession number P43358 (as available on September 2, 2024). MAGE-A4 localiza�on has been described as cytoplasmic. However, MAGE-A4 staining has also been detected in nuclei, with differen�al distribu�on between nucleus and cytoplasm in well-differen�ated versus less differen�ated cancers (Sarcevic et. al., Oncology, 2003, 64, 443-449). MAGE-A4 is used as a male germ cell marker. lt is not expressed in gonocytes, but expressed in pre-spermatogonia and mature germ cells (Mitchell et al., Mod. Pathol., 2014, 27, 1255-1266). Expression of the MAGE-A4 protein and mRNA has been linked to the development and prognosis of various cancers. The “MAGE-A8” or “Melanoma-associated an�gen 8” protein is a member of the MAGE-A superfamily and has the Uniprot accession number P43361 (as available on September 2, 2024). The “MAGE-A4” and “MAGE-A8” proteins have a sequence iden�ty of 72% as determined by a protein sequence alignment using the BLASTP 2.9.0 algorithm (Stephen et al., Nucleic Acids Res., 1997, 25:3389-3402). Furthermore, “MAGE-A4” and “MAGE-A8” both comprise the MAG-003 pep�de, i.e. “KVLEHVVRV” (SEQ ID NO: 57). It is evident for the skilled person that it is in par�cular envisaged herein that cancer is treated that presents the pep�de according to SEQ ID NO: 57 in complex with a MHC protein. Accordingly, it is envisaged that the herein described an�gen-binding proteins may comprise a TCR an�gen binding site (VR) that binds to the MAG-003 pep�de. In line with the above, it is envisaged that the an�gen-binding protein according to the inven�on may comprise a T cell receptor (TCR) alpha variable domain (Vα) as part of a TCR an�gen binding site (VR) that binds to the MAG-003 pep�de. “Vα“ and “Vα domain” may be used synonymously herein. The Vα domain may comprise a CDRα1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 62. The Vα domain may comprise a CDRα2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 63. The Vα domain may comprise a CDRα3 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 64. Said CDRs may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Accordingly, the an�gen-binding protein according to the inven�on may comprise a Vα domain comprising a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 62, a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 63 and / or a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 64. The an�gen-binding protein according to the inven�on may comprise a Vα domain comprising a CDRα1 consis�ng of the amino acid sequence according to SEQ ID NO: 62, a CDRα2 consis�ng of the amino acid sequence according to SEQ ID NO: 63 and / or a CDRα3 consis�ng of the amino acid sequence according to SEQ ID NO: 64. It is further envisaged that the an�gen-binding protein according to the inven�on comprises a TCR beta variable domain (Vβ) as part of a TCR an�gen binding site (VR) that binds to the MAG- 003 pep�de. “Vβ“ and “Vβ domain” may be used synonymously herein. The Vβ domain may comprise a CDRβ1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 59. The Vβ domain may comprise a CDRβ2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 60. The Vβ domain may comprise a CDRβ3 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 61. Said CDRs may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Accordingly, the an�gen-binding protein according to the inven�on may comprise a Vβ domain comprising a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 59, a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 60 and / or a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 61. The an�gen-binding protein according to the inven�on may comprise a Vβ domain comprising a CDRβ1 consis�ng of the amino acid sequence according to SEQ ID NO: 59, a CDRβ2 consis�ng of the amino acid sequence according to SEQ ID NO: 60 and / or a CDRβ3 consis�ng of the amino acid sequence according to SEQ ID NO: 61. Accordingly, it is envisaged that that the an�gen-binding protein according to the inven�on comprises a Vα and a Vβ wherein the Vα comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 62, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 63, and / or (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 64; and wherein the Vβ comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 59, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 60, and / or (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 61, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Furthermore, it is envisaged that the an�gen-binding protein according to the inven�on comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 54. It is envisaged that the an�gen-binding protein comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54. It is envisaged that the an�gen-binding protein comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 62, 63, and 64, respec�vely. It is envisaged that the an�gen-binding protein for use according to the inven�on comprises a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 53. It is also envisaged that the an�gen-binding protein comprises a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53. It is also envisaged that the an�gen-binding protein comprises a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 59, 60, and 61, respec�vely. Furthermore, it is envisaged that the an�gen-binding protein according to the inven�on comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 54 and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 53. Furthermore, it is envisaged that the an�gen-binding protein for use according to the inven�on comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 62, 63, and 64, respec�vely and a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 59, 60, and 61, respec�vely. Another preferred tumor associated an�gen that is bound by the an�gen-binding proteins described herein is the the PRAME an�genic pep�de comprising or consis�ng of the amino acid sequence “SLLQHLIGL” (SEQ ID NO: 58), more par�cularly, the PRAME an�genic pep�de comprising or consis�ng of the amino acid sequence “SLLQHLIGL” (SEQ ID NO: 58) in a complex with a MHC protein. “PRAME” or “Preferen�ally Expressed An�gen In Melanoma” wasfirst iden�fied as an an�gen that is overexpressed in melanoma (Ikeda et al Immunity.1997 Feb;6(2): 199-208); it is also known as CT130, MAPE, OIP-4 and has the Uniprot accession number P78395 (as available on January 11, 2019). The protein func�ons as a repressor of re�noic acid receptor signaling (Epping et al., Cell. 2005 Sep 23; 122(6):835-47). PRAME belongs to the family of germline- encoded an�gens known as cancer tes�s an�gens. Cancer tes�s an�gens are atrac�ve targets for immunotherapeu�c interven�on since they typically have limited or no expression in normal adult�ssues. PRAME is expressed in a number of solid tumors as well as in leukemia and lymphomas (Doolan et al., Breast Cancer Res Treat.2008 May; 109(2):359-65; Epping et al., Cancer Res.2006 Nov 15;66(22): 10639-42; Ercolak et al., Breast Cancer Res Treat.2008 May; 109(2):359-65; Matsushita et al., Leuk Lymphoma.2003 Mar;44(3):439-44; Mitsuhashi et al., Int. J Hematol. 2014; 100(1):88-95; Proto-Sequeire et al., Leuk Res. 2006 Nov;30(11): 1333-9; Szczepanski et al., Oral Oncol.2013 Feb;49(2): 144-51; Van Baren et al., Br J Haematol. 1998 Sep; 102(5): 1376-9). It is evident for the skilled person that it is in par�cular envisaged herein that cancer is treated that presents the pep�de according to SEQ ID NO: 58 in complex with a MHC protein. Accordingly, it is envisaged that the herein described an�gen-binding proteins comprise a TCR an�gen binding site (VR) that binds to the PRAME-004 pep�de. In line with the above, it is envisaged that the an�gen-binding protein according to the inven�on comprises a T cell receptor (TCR) alpha variable domain (Vα) as part of a TCR an�gen binding site (VR) that binds to the PRAME-004 pep�de. The Vα domain may comprise a CDRα1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 68. The Vα domain may comprise a CDRα2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 69. The Vα domain may comprise a CDRα3 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 70. Said CDRs may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Accordingly, the an�gen-binding protein according to the inven�on may comprise a Vα domain comprising a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 68, a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 69 and / or a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 70. The an�gen-binding protein according to the inven�on may comprise a Vα domain comprising a CDRα1 consis�ng of the amino acid sequence according to SEQ ID NO: 68, a CDRα2 consis�ng of the amino acid sequence according to SEQ ID NO: 69 and / or a CDRα3 consis�ng of the amino acid sequence according to SEQ ID NO: 70. It is further envisaged that the an�gen-binding protein according to the inven�on comprises a TCR beta variable domain (Vβ) as part of a TCR an�gen binding site (VR) that binds to the PRAME-004 pep�de. The Vβ domain may comprise a CDRβ1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 65. The Vβ domain may comprise a CDRβ2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 66. The Vβ domain may comprise a CDRβ3 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 67. Said CDRs may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Accordingly, the an�gen-binding protein according to the inven�on may comprise a Vβ domain comprising a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 65, a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 66 and / or a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 67. The an�gen-binding protein according to the inven�on may comprise a Vβ domain comprising a CDRβ1 consis�ng of the amino acid sequence according to SEQ ID NO: 65, a CDRβ2 consis�ng of the amino acid sequence according to SEQ ID NO: 66 and / or a CDRβ3 consis�ng of the amino acid sequence according to SEQ ID NO: 67. Accordingly, it is envisaged that that the an�gen-binding protein according to the inven�on comprises a Vα and a Vβ wherein the Vα comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 68, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 69, and / or (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 70; and wherein the Vβ comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 65, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 66, and / or (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 67, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. Furthermore, it is envisaged that the an�gen-binding protein according to the inven�on comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 56. It is envisaged that the an�gen-binding protein comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56. It is envisaged that the an�gen-binding protein comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 68, 69, and 70, respec�vely. It is envisaged that the an�gen-binding protein according to the inven�on comprises a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 55. It is also envisaged that the an�gen-binding protein comprises a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55. It is also envisaged that the an�gen-binding protein comprises a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 65, 66, and 67, respec�vely. Furthermore, it is envisaged that the an�gen-binding protein for use according to the inven�on comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 56 and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 55. Furthermore, it is envisaged that the an�gen-binding protein for use according to the inven�on comprises a Vα comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 68, 69, and 70, respec�vely and a Vβ comprising or consis�ng of an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 65, 66, and 67, respec�vely. It is envisaged that the an�gen-binding proteins in context of the inven�on consist or comprise of amino acid sequences of the an�gen-binding proteins as used in the appended examples. Accordingly, in par�cular embodiments, the inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 23 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 24. In par�cular, the inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 25 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 26. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 27 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 28. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 29 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 30. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 31 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 32. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 33 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 34. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 35 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 36. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 37 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 38. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 41 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 42. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 43 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 44. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 45 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 46. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 47 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 48. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 49 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 50. The inven�on relates to an an�gen binding protein comprising afirst polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 51 and a second polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NO: 52. Although evident for the skilled person it is pointed out that also nucleic acids and / or vectors encoding the herein described an�gen-binding proteins are encompassed by the inven�on. Addi�onally, nucleic acids and / or vectors encoding the herein described an�gen-binding proteins may be also used for the herein described uses and methods. Thus, the polypep�des of the an�gen-binding proteins may be encoded by nucleic acids and expressed in vivo, ex vivo or in vitro. The nucleic acid may be comprised in one nucleic acid molecule or may be separated into two or more nucleic acid molecules, wherein each nucleic acid molecule comprises at least one of the two or more sequences encoding the described an�gen-binding proteins. One nucleic acid molecule may encode one part or monomer of an an�gen-binding protein (for example one of two chains of a TCER®), and another nucleic acid molecule may encode another part or monomer of an an�gen-binding protein (for example the other one of two chains of the TCER®). The nucleic acid may encode two or more an�gen-binding protein polypep�de chains, for example, at least two polypep�des of a TCER®. Nucleic acids encoding mul�ple an�gen- binding protein polypep�de chains may include a nucleic acid cleavage site between at least two chain encoding sequences, may encode a transcrip�on or transla�on start site, such as an internal ribosomal entry site (IRES) between two or more chain sequences, and / or may encode a proteoly�c target site between two or more an�gen-binding protein chains. If two or more an�gen-binding protein polypep�de chains are encoded on one nucleic acid molecule, the two or more an�gen-binding protein polypep�de chains may be under the control of the same promoter or under the control of separate promoters. The term "nucleic acid" refers in the context of this inven�on to single- or double-stranded oligo- or polymers of deoxyribonucleo�de or ribonucleo�de bases or both. Nucleo�de monomers are composed of a nucleobase, afive-carbon sugar (such as but not limited to ribose or 2'-deoxyribose), and one to three phosphate groups. Typically, a nucleic acid is formed through phosphodiester bonds between the individual nucleo�de monomers. As used herein, the term nucleic acid includes but is not limited to ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) molecules but also includes synthe�c forms of nucleic acids comprising other linkages (e.g., pep�de nucleic acids as described in Nielsen et al. Science 254:1497-1500, 1991). Typically, nucleic acids are single- or double-stranded molecules and are composed of naturally occurring nucleo�des. The depic�on of a single strand of a nucleic acid also defines (at least par�ally) the sequence of the complementary strand. The nucleic acid may be single or double stranded or may contain por�ons of both double and single stranded sequences. Exemplified, double-stranded nucleic acid molecules can have 3' or 5' overhangs and as such are not required or assumed to be completely double-stranded over their en�re length. The term nucleic acid is used herein in the broadest sense and comprises chromosomes or chromosomal segments. Unless otherwise indicated, a par�cular nucleic acid sequence comprises or encodes complementary sequences, in addi�on to any sequence explicitly indicated. Preferably, the nucleic acid is an isolated nucleic acid. The nucleic acid may be a recombinant nucleic acid. The nucleic acids may be present in whole cells, in a cell lysate, or may be nucleic acids in a par�ally purified or substan�ally pure form. A nucleic acid is "isolated" or "rendered substan�ally pure" when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids or proteins, by standard techniques. Nucleic acid molecules of the disclosure may be obtained using standard molecular biology techniques, including but not limited to methods of amplifica�on, and reverse transcrip�on of RNA. Once DNA fragments encoding, for example, variable chains are obtained, these DNA fragments may be further manipulated by standard recombinant DNA techniques, for example to convert the variable region genes to full-length chain genes. In these manipulations, a variant-encoding DNA fragment is operatively linked to another DNA molecule, or to a fragment encoding another protein, such as a constant region or a flexible linker. The term "operatively linked", as used in this context, is intended to mean that the two DNA fragments are joined in a functional manner, for example, such that the amino acid sequences encoded by the two DNA fragments remain in-frame, or such that the protein is expressed under control of a desired promoter. The isolated DNA encoding the variable region, e.g. the variable alpha region and / or variable beta region, can be converted to a full- length chain gene by operatively linking the variable-encoding DNA to another DNA molecule encoding constant regions. The sequences of human constant region genes, e.g. for TCRs or antibodies, are known in the art and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The described nucleic acids may be included in one or more suitable vectors. If two or more antigen-binding protein polypeptide chains are encoded on one vector, the two or more antigen-binding protein polypeptide chains may be under the control of the same promoter or under the control of separate promoters. The terms "vector", "cloning vector" and "expression vector" refers to a vehicle by which a DNA or RNA sequence (e.g. a foreign gene) can be introduced into a host cell, so as to transform the host and promote expression (e.g. transcription and translation) of the introduced sequence. Various expression vectors may be employed to express the polynucleotides encoding the antigen-binding proteins. Both viral-based and non-viral expression vectors may be used to produce the antigen-binding proteins described herein in a mammalian host cell. Non-viral vectors and systems include plasmids, cosmids, episomes, and artificial chromosomes. Such vectors may comprise regulatory elements, such as a promoter, enhancer, terminator and the like, to cause or direct expression of said polypeptide upon administration to a subject. Examples of promoters and enhancers used in the expression vector for animal cell include early promoter and enhancer of SV40 (Mizukami et al. J Biochem., 1987, 101(5):1307-10), LTR promoter and enhancer of Moloney mouse leukemia virus (Kuwana et al. FEBS Let., 1987, 219(2):360-4), promoter (Mason et al. Cell., 1985, 41(2):479-87) and enhancer (Gillies et al. Cell., 1983, 33(3):717-28) of antibody heavy chain and the like. Examples of plasmids include replicating plasmids comprising an origin of replication, or integrative plasmids, such as for instance plIC, pcDNA, pBR and the like. The term “viral vector” refers to a nucleic acid vector construct that includes at least one element of viral origin and has the capacity to be packaged into a viral vector particle and encodes at least an exogenous nucleic acid. The vector and / or particle can be utilized for the purpose of transferring a nucleic acid of interest into cells either in vitro or in vivo. Numerous forms of viral vectors are known in the art. Useful viral vectors include vectors based on retroviruses, lentiviruses, adenoviruses, adeno-associated viruses, herpes viruses, vectors based on SV40, papilloma virus, Epstein Barr virus, vaccinia virus vectors and Semliki Forest virus (SFV). Recombinant viruses may be produced by techniques known in the art, such as by transfecting packaging cells or by transient transfection with helper plasmids or viruses. Typical examples of virus packaging cells include PA317 cells, PsiCRIP cells, GPenv+ cells, HEK293 cells, etc. Detailed protocols for producing such replication-defective recombinant viruses may be found for instance in WO95 / 14785, WO96 / 22378, US 5,882,877, US 6,013,516, US 4,861,719, US 5,278,056 and WO94 / 19478. Accordingly, the inven�on relates to a nucleic acid or separate nucleic acids encoding an an�gen-binding protein as described herein. In par�cular, the inven�on relates to a nucleic acid or separate nucleic acids encoding an an�gen-binding protein, wherein the the antigen-binding protein comprises a FC1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or a FC2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40. The inven�on further relates to a vector comprising the nucleic acid or the separate nucleic acids as described herein or separate vectors comprising the separate nucleic acids as described herein. In par�cular, the inven�on relates to a vector comprising a nucleic acid or separate nucleic acids, wherein the nucleic acid or the separate nucleic acids encode an an�gen-binding protein, wherein the the antigen-binding protein comprises a FC1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or a FC2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40. Also encompassed herein is a host cell comprising the described antigen-binding proteins, the described nucleic acid(s) or the described vector(s). The host cell may be transfected, infected, transduced or transformed, in particular with a nucleic acid and / or a vector as described herein. Accordingly, the inven�on relates to a host cell comprising the described an�gen- binding protein, the described nucleic acid or separate nucleic acids, or the described vector or the separate vectors. It is pointed out that the invention also relates to an antigen-binding protein as described herein, wherein the antigen-binding protein is produced by any one of the herein described host cells. Accordingly, the invention also relates to an antigen-binding protein, wherein the antigen-binding protein is produced by a host cell transfected with (a) nucleic acid(s) or (a) vector(s) encoding the herein described antigen-binding proteins. Thus, the invention relates to an antigen-binding protein, wherein the antigen-binding protein is produced by a) providing a suitable host cell, b) transfec�ng said suitable host cell with (a) nucleic acid(s) or (a) vector(s) encoding an antigen-binding protein as described herein, c) producing the antigen-binding protein, optionally d) harvesting the host cell, and e) purifying or isolating the antigen-binding protein. The invention relates to an antigen-binding protein, wherein the antigen-binding protein is produced by a) providing a suitable host cell, b) transfec�ng said suitable host cell with (a) nucleic acid(s) or (a) vector(s) encoding the antigen-binding protein, c) producing the antigen-binding protein, optionally d) harvesting the host cell, and e) purifying or isolating the antigen-binding protein, wherein wherein the antigen-binding protein comprises a FC1 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or a FC2 comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40. It is envisaged that the produced an�gen-binding proteins are further formulate into a pharmaceutical composition Thus, the invention relates to an antigen-binding protein, wherein the antigen-binding protein is produced by a) providing a suitable host cell, b) transfec�ng said suitable host cell with (a) nucleic acid(s) or (a) vector(s) encoding the antigen-binding protein as described herein, c) producing the antigen-binding protein, optionally d) harvesting the host cell, e) purifying or isolating the antigen-binding protein, and f) formulating the antigen-binding protein into a pharmaceutical composition. It is evident that the inven�on also relates to the an�gen-binding protein as obtained or obtainable by the herein described methods. The host cell is preferably a eukaryotic cell. The host cell may be a cultured cell or a primary cell, i.e., isolated directly from an organism, e.g., a human. The host cell can be an adherent cell or a suspended cell, i.e., a cell that grows in suspension. For purposes of producing a recombinant antigen-binding protein, for example a TCER®, the host cell is preferably a mammalian cell. The host cell for recombinant expression may be a Chinese Hamster Ovary (CHO) cell or a yeast cell. The host cell may also be a peripheral blood leukocyte (PBL) or a peripheral blood mononuclear cell (PBMC). The host cell may also be a lymphocyte, such as a T cell, a T cell progenitor or a NK cell. The invention also relates to pharmaceutical compositions. In particular the invention relates to pharmaceutical compositions comprising the herein described antigen-binding proteins. The terms "pharmaceu�cal composi�on" or "therapeu�c composi�on" as used herein refer to a compound or composi�on capable of inducing a desired therapeu�c effect when properly administered to a subject. The subject may also be referred to as pa�ent. Preferably, the subject is a mammal, more preferably a human. Such therapeu�c or pharmaceu�cal composi�ons may comprise a therapeu�cally effec�ve amount of an an�gen-binding protein, in admixture with a pharmaceu�cally or physiologically acceptable formula�on agent, carrier or aqueous medium selected for suitability with the mode of administra�on. The an�gen-binding protein will usually be supplied as part of a sterile, pharmaceu�cal composi�on which may include a pharmaceu�cally acceptable carrier. "Pharmaceu�cally" or "pharmaceu�cally acceptable" refers to molecular enes and composi�ons that do not produce an adverse, allergic or other untoward reac�on when administered to a mammal, especially a human, as appropriate. A pharmaceu�cally acceptable carrier or excipient refers to a non-toxic solid, semi-solid or liquidfiller, diluent, encapsula�ng material or formula�on auxiliary of any type. A “pharmaceu�cally-acceptable carrier” may also be referred to as “pharmaceu�cally acceptable diluent” or “pharmaceu�cally acceptable vehicle“ and may include solvents, bulking agents, stabilizing agents, dispersion media, coa�ngs, an�bacterial and an�fungal agents, isotonic and absorp�on delaying agents, and the like which are physiologically compa�ble. The carrier may be an aqueous carrier or an aqueous medium. The pharmaceu�cal composi�ons may be provided in a sealed container and may be provided as part of a kit. Such a kit would normally (although not necessarily) include instruc�ons for use. In par�cular, the pharmaceu�cal composi�ons may contain vehicles, which are pharmaceu�cally acceptable for a formula�on suitable for injec�on. These may be in par�cular isotonic, sterile, saline solu�ons (monosodium or disodium phosphate, sodium, potassium, calcium or magnesium chloride and the like or mixtures of such salts), or dry, especially freeze- dried composi�ons which upon addi�on, depending on the case, of sterilized water or physiological saline, permit the cons�tu�on of injectable solu�ons. To prepare pharmaceu�cal composi�ons, an effec�ve amount of the an�gen-binding protein may be dissolved or dispersed in a pharmaceu�cally acceptable carrier or aqueous medium. Accordingly, the inven�on relates to a pharmaceu�cal composi�on, wherein the herein described an�gen-binding protein is dissolved or dispersed in a pharmaceu�cally acceptable carrier or aqueous medium. The pharmaceu�cal forms suitable for injectable use include sterile aqueous solu�ons or dispersions; formula�ons including sesame oil, peanut oil or aqueous propylene glycol; and sterile powders for the extemporaneous prepara�on of sterile injectable solu�ons or dispersions. In all cases, the form must be sterile and must befluid to the extent that administra�on via a syringe is possible. It must be stable under the condi�ons of manufacture and storage and must be preserved against the contamina�ng ac�on of microorganisms, such as bacteria and fungi. Solu�ons of the ac�ve compounds as free base or pharmacologically acceptable salts can be prepared in water suitably mixed with a surfactant, such as hydroxypropylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary condi�ons of storage and use, these prepara�ons may contain a preserva�ve to prevent the growth of microorganisms. An an�gen binding protein described herein may be formulated into a composi�on in a neutral or salt form using pharmaceu�cally acceptable salts. Sterile injectable solu�ons are prepared by incorpora�ng the ac�ve compounds (an�gen- binding proteins) in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed byfiltered steriliza�on. Generally, dispersions are prepared by incorpora�ng the various sterilized ac�ve ingredients into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the prepara�on of sterile injectable solu�ons, the preferred methods of prepara�on are vacuum-drying and freeze-drying techniques which yield a powder of the ac�ve ingredient plus any addi�onal desired ingredient from a previously sterile-filtered solu�on thereof. The prepara�on of more, or highly concentrated solu�ons for direct injec�on is also contemplated, where the use of DMSO as solvent is envisioned to result in extremely rapid penetra�on, delivering high concentra�ons of the ac�ve agents to a small tumor area. It is pointed out that pharmaceu�cal composi�ons comprising the herein described nucleic acids, vectors and host cells are also encompassed. Accordingly, the inven�on relates to a pharmaceu�cal composi�on comprising the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell as described herein and / or the an�gen binding protein as obtained or obtainable by the herein described methods. The inven�on also relates to the use of the described an�gen-binding proteins nucleic acids, vectors, host cells and / or pharmaceu�cal composi�ons in the manufacture of a medicament. The inven�on also relates to the use of the described an�gen-binding protein, nucleic acids, vectors, host cells and / or pharmaceu�cal composi�ons in the manufacture of a medicament for the treatment of cancer. The inven�on also relates to the described an�gen-binding protein, nucleic acids, vectors, host cells and / or pharmaceu�cal composi�ons for use in medicine. The inven�on further relates to the described an�gen-binding protein, nucleic acids, vectors, host cells and / or pharmaceu�cal composi�ons for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. In par�cular the inven�on relates to an RNA encoding the described an�gen-binding proteins as well as a pharmaceu�cal composi�on comprising an RNA encoding the described an�gen- binding proteins for use in medicine. Accordingly, the inven�on in par�cular relates to an RNA encoding the described an�gen-binding proteins as well as a pharmaceu�cal composi�on comprising an RNA encoding the described an�gen-binding proteins for use use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. Although evident for the skilled person it is pointed out that the disclosures in context of the methods described herein are disclosed as corresponding use muta�s mutandis. The disclosures in context of the use described herein are disclosed as corresponding methods muta�s mutandis. Accordingly, the inven�on relates to a method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the described an�gen-binding protein, pharmaceu�cal composi�on, nucleic acid or separate nucleic acids, vector or the separate vectors, the host cell and / or the an�gen-binding protein as obtained or obtainable by the described methods to a pa�ent in need thereof. The inven�on also relates to a pharmaceu�cal composi�on / formula�on for use in a method of trea�ng a condi�on or disease by producing an an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on / formula�on comprises a nucleic acid encoding the two an�gen-binding protein and wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on / formula�on. Preferably, the nucleic acid is a mRNA. The inven�on also relates to a method comprising administering to a subject in need thereof a pharmaceu�cal composi�on comprising the herein described an�gen-binding protein or a nucleic acid encoding the herein described an�gen-binding protein. The inven�on also relates to a method of efficient protein produc�on in a cell popula�on, the method comprising contac�ng a cell popula�on with a nucleic acid encoding the herein described an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid under condi�ons such that an effec�ve amount of the an�gen-binding protein is produced in the cell popula�on. The inven�on also relates to a method for inducing in vivo transla�on of the described an�gen- binding proteins in a mammalian subject in need thereof, comprising administering to the subject an effec�ve amount of a nucleic acid encoding the herein described an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid under condi�ons such that the nucleic acid is localized into a cell of the subject and the an�gen-binding proteins are capable of being translated in the cell from the nucleic acid. In addi�on the inven�on relates to a method of muta�ng an an�gen-binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. As shown in the appended examples the described amino acid subs�tu�ons can increase / improve heterodimerisa�on, increase / improve the stability, increase / improve the yield and / or increase / improve the purity of the corresponding an�gen-binding proteins. Accordingly, the inven�on relates to a method of increasing the heterodimerisa�on of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3- containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. The inven�on also relates to a method of increasing the stability of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. Addi�onally, the inven�on relates to a method of increasing the yield of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. Furthermore, the inven�on relates to a method of increasing the purity of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein. The inven�on also relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 409 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 392 by aspar�c acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 399 by lysine and the subs�tu�on of the amino acid at posi�on 356 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 409 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 392 by aspar�c acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 399 by lysine and the subs�tu�on of the amino acid at posi�on 356 by lysine and the amino acid variant Y349C. The inven�on further relates to an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 394 by aspar�c acid, the subs�tu�on of the amino acid at posi�on 395 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 396 by aspar�c acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 395 by lysine, the subs�tu�on of the amino acid at posi�on 396 by lysine and the subs�tu�on of the amino acid at posi�on 397 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 394 by aspar�c acid, the subs�tu�on of the amino acid at posi�on 395 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 396 by aspar�c acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 395 by lysine, the subs�tu�on of the amino acid at posi�on 396 by lysine and the subs�tu�on of the amino acid at posi�on 397 by lysine and the amino acid variant Y349C. As also demonstrated in the appended Example 2 the herein described an�gen-binding proteins can be excellently co-expressed with other heteromeric proteins, in par�cular other heterodimeric an�gen-binding proteins. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, comprising (i) cul�va�ng the host cell, (ii) producing the an�gen-binding proteins, and op�onally (iii) harves�ng the host cell, and preferably (iv) isola�ng the an�gen-binding proteins, wherein the host cell comprises a nucleic acid encoding afirst an�gen-binding protein comprising at least one heteromeriza�on improving amino acid subs�tu�on and a nucleic acid encoding a second an�gen-binding protein comprising at least one heteromeriza�on improving subs�tu�on. The described methods relate to methods performed in vivo, ex vivo or in vitro. The methods may be used to recombinantly produce two an�gen-binding proteins simultaneously e.g. in a fermenter. The skilled person understands that in this case steps (iii) and (iv) may be relevant. However, especially, it is envisaged that a nucleic acid encoding afirst an�gen-binding protein and a nucleic acid encoding a second an�gen-binding protein are together administered to a pa�ent and that the cells of said pa�ent produce said two an�gen-binding proteins. The skilled person understands that in this case steps (iii) and (iv) are not relevant. In par�cular, it is envisaged that the heteromeric an�gen-binding proteins are heterodimers and the heteromeriza�on improving amino acid subs�tu�ons are heterodimeriza�on improving amino acid subs�tu�ons. It is envisaged that in the described methods one of the at least two an�gen-binding proteins is an an�gen-binding protein as described above. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein one of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. In par�cular it is envisaged that in the described methods for producing at least two an�gen- binding proteins one an�gen-binding protein is an an�gen-binding protein as already described above and the other an�gen-binding protein is an an�gen-binding proteins that also comprises two IgG CH3-containing polypep�des. It is envisaged that said other an�gen-binding proteins comprising two IgG CH3-containing polypep�des comprises at least one heteromeriza�on improving amino acid subs�tu�on, preferably in the CH3-domain. A “heteromeriza�on improving amino acid subs�tu�on” refers to an amino acid subs�tu�on that facilitates the interac�on of two polypep�des or in other words facilitates the binding of the polypep�des to each other. It is in par�cular envisaged that the heteromeriza�on improving amino acid subs�tu�ons of said other an�gen-binding protein are so-called “knob-into-hole” muta�ons (US5731168 and US8216805). However, it is also envisaged that the heteromeriza�on improving amino acid subs�tu�ons of said other an�gen-binding protein are the amino acid subs�tu�ons described herein. Example 3 demonstrates that also two of the described an�gen-binding proteins can be co-expressed, preferably two an�gen-binding proteins with different of the described heteromeriza�on improving amino acid subs�tu�on. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein one of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; and the other of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein one of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and the other of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. In a preferred embodiment, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein one of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; and the other of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant S354C; and the other of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant S354C. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C; and the other of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C. In a preferred embodiment, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen- binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C; and the other of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant S354C. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1; and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 2 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39; and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40. In a preferred embodiment, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen- binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1; and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 39 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 40. As men�oned above and as also shown in the appended Examples the described amino acid subs�tu�ons can be combined with knob-into-hole amino acid subs�tu�ons for co-expression of two heteromeric proteins. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein one of the at least two an�gen-binding proteins is an an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and the other of the at least two an�gen-binding proteins is an an�gen-binding protein comprising knob-into-hole amino acid subs�tu�ons. The knob-into-hole subs�tu�ons usually are T366W (knob) in one polypeptide and T366S, L368A and Y407V (hole) in the other polypeptide. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variant T366W and the second polypep�de comprises the amino acid variants T366S, L368A and Y407V. In the described methods the second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprising the knob-into-hole subs�tu�ons may further comprise addi�onal heteromeriza�on improving amino acid subs�tu�ons, e.g. introduced disulphide bridges. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variant S354C and T366W and the second polypep�de comprises the amino acid variants Y349C, T366S, L368A and Y407V. The inven�on relates to a method for producing at least two different heteromeric an�gen- binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variant S354C and T366W and the second polypep�de comprises the amino acid variants Y349C, T366S, L368A and Y407V. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variant S349C and T366W and the second polypep�de comprises the amino acid variants Y354C, T366S, L368A and Y407V. Again it is pointed out that it is evident for the skilled person that the amino acid posi�ons provided above are not necessarily the posi�ons in the described protein but refer to the corresponding posi�on in a (wildtype / na�ve) IgG an�body. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein the CH3 domain of thefirst polypep�de has aspar�c acid at the posi�on corresponding to posi�on 351 in an IgG an�body, glutamic acid at the posi�on corresponding to posi�on 368 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 349 in an IgG an�body; and the CH3 domain of the second polypep�de has lysine at the posi�on corresponding to posi�on 351 in an IgG an�body, lysine at the posi�on corresponding to posi�on 366 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 354 in an IgG an�body; or the CH3 domain of thefirst polypep�de has aspar�c acid at the posi�on corresponding to posi�on 351 in an IgG an�body, glutamic acid at the posi�on corresponding to posi�on 368 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 354 in an IgG an�body; and the CH3 domain of the second polypep�de has lysine at the posi�on corresponding to posi�on 351 in an IgG an�body, lysine at the posi�on corresponding to posi�on 366 in an IgG an�body, and cysteine at the posi�on corresponding to posi�on 349 in an IgG an�body; and a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein the CH3 domain of thefirst polypep�de has cysteine at the posi�on corresponding to posi�on 354 in an IgG an�body, and tryptophan at the posi�on corresponding to posi�on 366 in an IgG an�body, and the CH3 domain of second polypep�de has cysteine at the posi�on corresponding to posi�on 349 in an IgG an�body, serine at the posi�on corresponding to posi�on 366 in an IgG an�body, alanine at the posi�on corresponding to posi�on 368 in an IgG an�body, and valine at the posi�on corresponding to posi�on 407 in an IgG an�body. It is in par�cular envisaged that the second an�gen-binding protein comprises two IgG CH3- containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18. It is pointed out that when it is referred to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17” also the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17 and the amino acid variants S354C and T366W” is encompassed. Similarly, when it is referred to “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18” also the wording “an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18 and the amino acid variants Y349C, T366S, L368A and Y407V” is encompassed. The inven�on, thus, relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or 39 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-FC2 wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL; and wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1 or 39; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: V5-L5-V6-FC3 and the second polypep�de comprises a structure represented by the formula: V7-L6-V8-FC4 wherein L5 and L6 are linkers and may be the same or different, wherein V5 is Vα, V6 is VH, V7 is VL, V4 is Vβ; V5 is VL, V6 is Vα, V7 is Vβ, V8 is VH; V5 is Vβ, V6 is VL, V7 is VH, V8 is Vα; V5 is VH, V6 is Vα, V7 is Vβ, V8 is VL; V5 is Vα, V6 is VL, V7 is VH, V8 is Vβ; V5 is VL, V6 is Vβ, V7 is Vα, V8 is VH; V5 is Vβ, V6 is VH, V7 is VL, V8 is Vα; or V5 is VH, V6 is Vβ, V7 is Vα, V8 is VL; and wherein FC3 comprises or consists of the amino acid sequence according to SEQ ID NO: 17 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 17; and / or FC4 comprises or consists of the amino acid sequence according to SEQ ID NO: 18 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 18; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 2 or 40. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC1 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 18; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 2 or 40. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 18. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 53, FC1 comprises or consists of SEQ ID NO: 17; Vα comprises or consists of the amino acid according to SEQ ID NO: 54, VH comprises or consists of the amino acid according to SEQ ID NO: 9 and FC2 comprises or consists of SEQ ID NO: 18; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises a structure represented by the formula: VL-L1-Vβ-FC2 ; and the second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC1 ; wherein L1 and L2 are linkers and comprise or consist of the amino acid according to SEQ ID NO: 16, VL comprises or consists of the amino acid according to SEQ ID NO: 5, Vβ comprises or consists of the amino acid according to SEQ ID NO: 55, FC1 comprises or consists of SEQ ID NO: 1 or 39; Vα comprises or consists of the amino acid according to SEQ ID NO: 56, VH comprises or consists of the amino acid according to SEQ ID NO: 13 and FC2 comprises or consists of SEQ ID NO: 2 or 40. The skilled person understands that in the described an�gen-binding proteins comprising the knob-into-hole subs�tu�ons the cysteines forming a disulphide bridge may be exchanged / flipped between the CH3-domain containing polypep�des, i.e. the first polypep�de comprises the amino acid variant S349C and T366W and the second polypep�de comprises the amino acid variants Y354C, T366S, L368A and Y407V. In par�cular the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 41 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 42; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 49 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 50. In par�cular the inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 41 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 42; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 51 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 52. In par�cular the inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 43 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 44; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 47 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 48. In par�cular the inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 45 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 46; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 47 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 48. The inven�on also relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 25 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 26; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein thefirst polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 27 and the second polypep�de comprises or consists of an amino acid sequence according to SEQ ID NO: 28. It is also envisaged that the Fc parts of the disclosed an�gen-binding proteins are exchanged between the CH3-domain containing polypep�des. The skilled person is readily capable to determine the FC1 and / or FC2 in the disclosed an�gen-binding proteins and knows that these regions may be exchanged between the CH3-domain containing polypep�des. In other words when a herein described an�gen-binding protein comprises afirst IgG CH3-containing polypep�de comprising FC1 and a second IgG CH3-containing polypep�de comprising FC2 also the an�gen-binding protein with FC2 infirst IgG CH3-containing polypep�de and FC1 in the second IgG CH3-containing polypep�de is disclosed. It is envisaged that the described an�gen-binding proteins are combined with further an�gen- binding proteins having further target an�gens. In par�cular, it is envisaged that the described an�gen-binding proteins targe�ng MAG-003 and / or PRAME-004 are combined with further an�gen-binding proteins having further target an�gens. Thus, the inven�on also relates to a method for producing at least three different heteromeric an�gen-binding proteins in a single host cell, wherein one an�gen-binding protein of the at least three different heteromeric an�gen-binding proteins binds to MAG-003. The inven�on also relates to a method for producing at least three different heteromeric an�gen-binding proteins in a single host cell, wherein one an�gen-binding protein of the at least three different heteromeric an�gen- binding proteins binds to PRAME-004. The inven�on also relates to a method for producing at least three different heteromeric an�gen-binding proteins in a single host cell, wherein one an�gen-binding protein of the at least three different heteromeric an�gen-binding proteins binds to MAG-003 and another an�gen-binding protein of the at least three different heteromeric an�gen-binding proteins binds to PRAME-004. Also an�gen-binding proteins harboring other heteromeriza�on improving amino acid subs�tu�ons are envisaged to be co-expressed with the above described an�gen-binding proteins. Said other heteromeriza�on improving amino acid subs�tu�ons may be those described in WO2009 / 089004. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variants K409D and K392D and the second polypep�de comprises the amino acid variants D399K and E356K, optionally wherein the second an�gen- binding protein comprises further ar�ficial disulphide bridges as described herein. The inven�on, thus, relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 21 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 21 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 22 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 22. It is also envisaged that an�gen-binding proteins harboring the heteromeriza�on improving amino acid subs�tu�ons as described in WO2017 / 034770 are co-expressed with the above described an�gen-binding proteins. Accordingly, the inven�on relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein the first polypep�de comprises the amino acid variant T394D, P395D and P396D and the second polypep�de comprises the amino acid variants P395K, P396K and V397K, optionally wherein the second an�gen-binding protein comprises further ar�ficial disulphide bridges as described herein. The inven�on, thus, relates to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, wherein afirst an�gen-binding protein of the at least two different heteromeric an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant Y349C; and wherein a second an�gen-binding protein of the least two different heteromeric an�gen- binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 19 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 19 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 20 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 20. Although evident for the skilled person it is pointed out that the inven�on also relates to the an�gen-binding proteins as obtained or obtainable by the above described methods. Similarly the inven�on relates to a pharmaceu�cal composi�on comprising at least two of the an�gen-binding proteins as defined herein or as produced by the herein described methods. The inven�on also relates a pharmaceu�cal composi�on comprising a nucleic acid or separate nucleic acids encoding at least two of the an�gen-binding proteins as defined herein. Again, it is men�oned that the inven�on also relates to the described pharmaceu�cal composi�on for use in medicine, in par�cular for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. Accordingly, the inven�on also relates to a method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the described pharmaceu�cal composi�ons to a pa�ent in need thereof. As men�oned above it is in par�cular envisaged that the described an�gen-binding proteins are co-expressed in a pa�ent, preferably a human. Accordingly, in further embodiments of the inven�on, all the methods described herein directed to a method for producing at least two different heteromeric an�gen-binding proteins in a single host cell also refer to a method of treatment, wherein nucleic acids encoding said an�gen-binding proteins are administered to a pa�ent and the cells of the pa�ent produce said an�gen-binding proteins. The herein described an�gen-binding proteins described herein a par�cularly useful for such applica�on because the present inventors showed that said an�gen-binding proteins have excellent heterodimerisa�on proper�es and do not form incorrectly assembled dimers when co-expressed. Accordingly the inven�on relates to a pharmaceu�cal composi�on / formula�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on / formula�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins and wherein the method comprises contac�ng a cell, �ssue or organism with the pharmaceu�cal composi�on / formula�on. Preferably, the nucleic acid is a mRNA. For example, the inven�on relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or 39 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18. The inven�on also relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 1 or 39 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 2 or 40; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 17 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 18, and wherein one of the an�gen-binding proteins binds to the pep�de according to SEQ ID NO: 57 and the other an�gen-binding proteins binds to the pep�de according to SEQ ID NO: 58. In par�cular it is envisaged that the TCER® molecules of Table 1 targe�ng MAG-003 or PRAME- 004, respec�vely, are combined in the herein described methods of trea�ng. It is evident that in par�cular the combina�on of TPP-9501 with TPP-9505 or TPP-9506 and the combina�on of TPP-9504 with TPP-9502 or TPP-9503 is envisaged. Accordingly, the inven�on also relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 41 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 42; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 49 or 51 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 50 or 52. The inven�on further relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 47 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 48; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 43 or 45 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 44 or 46. Target antigen T-cell Mutation sets “Disulphide” TPP # of TCR variable Recruiting substitutions domain Domain MAG-003 SEQ ID NOs: 5 Knob-into- S354C / Y349'C TPP-9501 (R7P1D5- + 9 hole (SEQ ID NOs: derived) (BMA031(V36)) 41 + 42) MAG-003 SEQ ID NOs: 5 L351D:L368E / Y349C / S354'C TPP-9502 (R7P1D5- + 9 L351'K:T366'K (SEQ ID NOs: derived) (BMA031(V36)) 43 + 44) MAG-003 SEQ ID NOs: 5 L351D:L368E / S354C / Y349'C TPP-9503 (R7P1D5- + 9 L351'K:T366'K (SEQ ID NOs: derived) (BMA031(V36)) 45 + 46) PRAME-004 SEQ ID NOs: 5 Knob-into- S354C / Y349'C TPP-9504 (R11P3D3- + 13 hole (SEQ ID NOs: derived) (BMhanced) 47 + 48) PRAME-004 SEQ ID NOs: 5 L351D:L368E / Y349C / S354'C TPP-9505 (R11P3D3- + 13 L351'K:T366'K (SEQ ID NOs: derived) (BMhanced) 49 + 50) PRAME-004 SEQ ID NOs: 5 L351D:L368E / S354C / Y349'C TPP-9506 (R11P3D3- + 13 L351'K:T366'K (SEQ ID NOs: derived) (BMhanced) 51 + 52) Table 1: MAG-003 and PRAME-004 targe�ng TCER®s partly with the herein described heterodimerisa�on improving subs�tu�ons in the CH3-domain. The disulphide subs�tu�ons may be exchanged between the polypep�de chains. Accordingly, also the amino acid sequences of the polypep�des with the exchanged disulphide subs�tu�ons are considered to be encompassed / disclosed herein. For example, SEQ ID NOs: 41 is disclosed with S354C but the same sequence with Y349C is also encompassed (i.e. the sequence with a serine at the posi�on corresponding to posi�on 354 and cysteine at the posi�on corresponding to posi�on 349). It is evident for the skilled person that the an�gen-binding molecules of Table 1 contain a C- terminal Strep-Tag. Accordingly, it is evident for the skilled person that when said an�gen- binding molecules are used in medical or therapeu�c se�ngs the an�gen-binding molecules without Strep-Tag may be preferred. Table 1A shows the sequences of the an�gen-binding proteins of Table 1 without Strep-Tag. Accordingly, it is evident for the skilled person that the an�gen-binding proteins shown in Table 1A may be preferred for medical or therapeu�c se�ngs. Target antigen T-cell Mutation sets “Disulphide” SEQ ID NO of TCR variable Recruiting substitutions domain Domain MAG-003 SEQ ID NOs: 5 Knob-into- S354C / Y349'C MAG-003 (R7P1D5- + 9 hole TCER® (SEQ derived) (BMA031(V36)) ID NOs: 79 + 76) MAG-003 SEQ ID NOs: 5 L351D:L368E / Y349C / S354'C TPP-9502 (R7P1D5- + 9 L351'K:T366'K untagged derived) (BMA031(V36)) (SEQ ID NOs: 80 + 81) MAG-003 SEQ ID NOs: 5 L351D:L368E / S354C / Y349'C TPP-9503 (R7P1D5- + 9 L351'K:T366'K untagged derived) (BMA031(V36)) (SEQ ID NOs: 82 + 83) PRAME-004 SEQ ID NOs: 5 Knob-into- S354C / Y349'C PRAME-004 (R11P3D3- + 13 hole TCER® (SEQ derived) (BMhanced) ID NOs: 74 + 72) PRAME-004 SEQ ID NOs: 5 L351D:L368E / Y349C / S354'C TPP-9505 (R11P3D3- + 13 L351'K:T366'K untagged derived) (BMhanced) (SEQ ID NOs: 84 + 85) PRAME-004 SEQ ID NOs: 5 L351D:L368E / S354C / Y349'C TPP-9506 (R11P3D3- + 13 L351'K:T366'K (SEQ ID NOs: derived) (BMhanced) 86 + 87) Table 1A: MAG-003 and PRAME-004 targe�ng TCER®s partly with the herein described heterodimerisa�on improving subs�tu�ons in the CH3-domain. The disulphide subs�tu�ons may be exchanged between the polypep�de chains. Accordingly, also the amino acid sequences of the polypep�des with the exchanged disulphide subs�tu�ons are considered to be encompassed / disclosed herein. Accordingly, the inven�on also relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 79 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 76; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 84 or 86 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 85 or 87. The inven�on further relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on, wherein afirst an�gen-binding protein of the at least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 74 and the other polypep�de comprises the amino acid sequence according to SEQ ID NO: 72; and wherein a second an�gen-binding protein of the least two an�gen-binding proteins comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acid sequence according to SEQ ID NO: 80 or 82 and the other polypeptide comprises the amino acid sequence according to SEQ ID NO: 81 or 83. The inven�on also relates to a method comprising administering to a subject in need thereof a pharmaceu�cal composi�on comprising at least two of the herein described an�gen-binding proteins or nucleic acids encoding at least two of the herein described an�gen-binding proteins. The inven�on also relates to a method of efficient protein produc�on in a cell popula�on, the method comprising contac�ng a cell popula�on with nucleic acids encoding at least two of the herein described an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acids under condi�ons such that an effec�ve amount of the protein is produced in the cell popula�on. The inven�on also relates to a method for inducing in vivo transla�on of at least two (recombinant) an�gen-binding proteins in a mammalian subject in need thereof, comprising administering to the subject an effec�ve amount of (a) nucleic acid(s) encoding at least two of the herein described an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid(s) under condi�ons such that the nucleic acid(s) is / are localized into a cell of the subject and the an�gen-binding proteins are capable of being translated in the cell from the nucleic acid(s). The inven�on also relates to kits comprising the described an�gen-binding proteins, nucleic acids, vectors, host cells or pharmaceu�cal composi�ons / formula�ons. Suitable pharmaceu�cal composi�ons and modifica�ons of the nucleic acids that allow treatment of pa�ents by the above described uses and methods are described e.g. in WO2012 / 019168, WO2013 / 151663 or WO2013 / 151665 which are incorporated by reference in their en�rety. As men�oned above, the inven�on also relates to an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins for use as medicine. The an�gen-binding proteins may be administered or co-administered, simultaneously, in either separate or combined formula�ons, or sequen�ally at different�mes separated by minutes, hours or days, but in some way act together to provide the desired therapeu�c response. The inven�on also relates to an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC), preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. The inven�on also relates to a combina�on comprising an an�gen-binding protein binding to MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins. The inven�on also relates to a pharmaceu�cal composi�on comprising an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins. The inven�on also relates to a pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding at least two an�gen-binding proteins, wherein the method comprises contac�ng a cell,�ssue or organism with the pharmaceu�cal composi�on and wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein. The inven�on also relates to an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins. The inven�on also relates to an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins. “Co-administra�on”, “administered in combina�on”, “administra�on of a combina�on”, “co-administra�on of a combina�on”, “combined therapy” and / or “combined treatment regimen” is used herein in the broadest sense and refers to at least two therapeu�cally ac�ve drugs or composi�ons which may be administered or co- administered, simultaneously, in either separate or combined formula�ons, or sequen�ally at different�mes separated by minutes, hours or days, but in some way act together to provide the desired therapeu�c response. Accordingly, the described an�gen-binding proteins may be administered or co-administered, simultaneously, in either separate or combined formula�ons, or sequen�ally at different�mes separated by minutes, hours or days. Simultaneous administra�on means that the therapeu�cally ac�ve agents (the described an�gen-binding proteins) can be administered at the same�me. This can occur either by combining them into a single formula�on / composi�on or by administering them separately but concurrently or concomitantly. The described an�gen-binding proteins may be administered in separate formula�ons which means that the ac�ve agents may be provided in different formula�ons / composi�ons, meaning each drug or composi�on retains its own dis�nct form. Even though they are administered together or in close succession, they are not physically combined into one dosage form (e.g. pharmaceu�cal composi�on). Sequen�al Administra�on means that the described an�gen-binding proteins are administered at different�mes. This could mean administering them minutes, hours or even days apart. Despite this staggered�ming, the agents are considered part of a combined therapy because they interact or work in concert to achieve the desired therapeu�c effect. The skilled person knows that the key aspect of these combined approaches is that, regardless of the�ming or method of delivery, the ac�ve agents may act in synergy or complement each other in a way that contributes to the intended therapeu�c outcome or therapeu�c effect. Accordingly, the inven�on relates to the described an�gen-binding proteins for use in the treatment of cancer, wherein the an�gen-binding proteins are administered in combina�on, wherein the an�gen-binding proteins are each present in an amount effec�ve to achieve a synergis�c therapeu�c effect when administered in combina�on. The inven�on also relates to a method of protein produc�on in a cell popula�on, wherein the method comprises contac�ng a cell popula�on with a nucleic acid or nucleic acids encoding at least two an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids under condi�ons such that an effec�ve amount of the protein is produced in the cell popula�on, wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein. The inven�on also relates to a method for inducing in vivo transla�on of at least two an�gen- binding proteins in a mammalian subject in need thereof, comprising administering to the subject an effec�ve amount of a nucleic acid or nucleic acids encoding the at least two an�gen- binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids under condi�ons such that the nucleic acid(s) is / are localized into a cell of the subject and the an�gen-binding proteins are capable of being translated in the cell from the nucleic acid(s), wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein and an an�gen- binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein, preferably a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein and op�onally one or more further an�gen-binding proteins. Although evident for the skilled person it is pointed out that in the above described embodiments the an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and the an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) and op�onally one or more further an�gen-binding proteins act together to provide a desired therapeu�c effect. In par�cular the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may comprise a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 62, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 63, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 64; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 59, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 60, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 61, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may also comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 54 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 62, 63, and 64, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 53 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 59, 60, and 61, respec�vely. Furthermore, the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may comprise an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may further comprise a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may comprises or consists of afirst polypep�de chain comprising a structure represented by the formula: VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different. L1 and / or L2 may comprise or consist of an amino acid sequence according to SEQ ID NO: 16. FC1 may comprise or consist of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 may comprise or consist of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein may comprise a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 75, 79, 80 or 82 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76, 81 or 83. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 68, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 69, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 70; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 65, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 66, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 67, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 56 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 68, 69, and 70, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 55 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 65, 66, and 67, respec�vely. The an�gen-binding protein binding to a pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise or consist of afirst polypep�de chain comprising a structure represented by the formula: VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different. L1 and / or L2 may comprise or consist of an amino acid sequence according to SEQ ID NO: 16. FC1 may comprise or consist of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 comprise or consist of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40. The an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein may comprise a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 71, 74, 84 or 86 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72, 85 or 87. In a preferred embodiment, the inven�on relates to an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 for use as medicine. In another preferred embodiment, the inven�on relates to an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. In another preferred embodiment, the inven�on relates to a combina�on comprising an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72. In another preferred embodiment, the inven�on relates to a combina�on comprising an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders. In another preferred embodiment, the inven�on relates to a pharmaceu�cal composi�on comprising an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72. In another preferred embodiment, inven�on relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72. In another preferred embodiment, the inven�on relates to an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72. In another preferred embodiment, the inven�on relates to an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76. The described an�gen-binding proteins may be administered in doses as described in EP24174662.7, EP24199013.4, EP25151617.5, EP24213284.3 and EP25166821.6 which are incorporated herein by reference in its en�rety. In par�cular, the an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 may be administered at a dose of about 10 µg, about 20 µg, about 30 µg, about 40 µg, about 50 µg, about 60 µg, about 80 µg, about 100 µg, about 120 µg, about 140 µg, about 150 µg, about 160 µg, about 180 µg, about 200 µg, about 250 µg, about 300 µg, about 350 µg, about 360 µg, about 400 µg, about 450 µg, about 500 µg, about 540 µg, about 550 µg, about 600 µg, about 800 µg, about 1200 µg, about 1500 µg, about 1600 µg, about 1800 µg, about 2500 µg, about 3000 µg, about 3500 µg, about 4000 µg, about 4500 µg, about 5000 µg, about 5500 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg, about 15 mg, about 16 mg, about 17 mg, about 18 mg, about 19 mg, about 20 mg, about 21 mg, about 22 mg, about 23 mg, about 24 mg, about 25 mg, about 26 mg, about 27 mg, about 28 mg, about 29 mg, about 30 mg, about 31 mg, about 32 mg, about 33 mg, about 34 mg, about 35 mg, about 36 mg, about 37 mg, about 38 mg, about 39 mg, about 40 mg, about 41 mg, about 42 mg, about 43 mg, about 44 mg, about 45 mg, about 46 mg, about 47 mg, about 48 mg, about 49 mg or about 50 mg, preferably about 20 µg, about 60 µg, about 120 µg, about 360 µg, about 800 µg, about 1600 µg, about 3000 µg, about 3500 µg, about 4000 µg, about 4500 µg, about 5000 µg, about 5500 µg, or about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg, about 15 mg, about 16 mg, about 17 mg, about 18 mg, about 19 mg or about 20 mg, more preferably about 1600 µg, about 3000 µg, about 4000 µg, about 5000 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg or about 15 mg. In par�cular, the an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 may be administered at a dose of about 6.6 µg, about 10 µg, about 20 µg, about 30 µg, about 40 µg, about 50 µg, about 60 µg, about 80 µg, about 100 µg, about 120 µg, about 140 µg, about 150 µg, about 160 µg, about 180 µg, about 200 µg, about 250 µg, about 300 µg, about 350 µg, about 400 µg, about 450 µg, about 500 µg, about 540 µg, about 600 µg, about 1000 µg, about 1200 µg, about 1800 µg or about 2500 µg, about 5000 µg, or about 10 mg, preferably about 6.6 µg, about 20 µg, about 60 µg, about 180 µg, about 300 µg, about 540 µg, about 600 µg, about 1000 µg, about 1200 µg, about 1800 µg, about 2000 µg, about 2500 µg, about 5000 µg, or about 10 mg more preferably about 1200 µg, about 1800 µg, about 2000 µg or about 2500 µg, or about 1000 µg to about 2500 µg or about 1200 µg to about 2500 µg. Accordingly, the inven�on relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 6.6 µg, about 10 µg, about 20 µg, about 30 µg, about 40 µg, about 50 µg, about 60 µg, about 80 µg, about 100 µg, about 120 µg, about 140 µg, about 150 µg, about 160 µg, about 180 µg, about 200 µg, about 250 µg, about 300 µg, about 350 µg, about 400 µg, about 450 µg, about 500 µg, about 540 µg, about 600 µg, about 1000 µg, about 1200 µg, about 1800 µg or about 2500 µg, about 5000 µg, or about 10 mg, preferably about 6.6 µg, about 20 µg, about 60 µg, about 180 µg, about 300 µg, about 540 µg, about 600 µg, about 1000 µg, about 1200 µg, about 1800 µg, about 2000 µg, about 2500 µg, about 5000 µg, or about 10 mg more preferably about 1200 µg, about 1800 µg, about 2000 µg or about 2500 µg, or about 1000 µg to about 2500 µg or about 1200 µg to about 2500 µg and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 10 µg, about 20 µg, about 30 µg, about 40 µg, about 50 µg, about 60 µg, about 80 µg, about 100 µg, about 120 µg, about 140 µg, about 150 µg, about 160 µg, about 180 µg, about 200 µg, about 250 µg, about 300 µg, about 350 µg, about 360 µg, about 400 µg, about 450 µg, about 500 µg, about 540 µg, about 550 µg, about 600 µg, about 800 µg, about 1200 µg, about 1500 µg, about 1600 µg, about 1800 µg, about 2500 µg, about 3000 µg, about 3500 µg, about 4000 µg, about 4500 µg, about 5000 µg, about 5500 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg, about 15 mg, about 16 mg, about 17 mg, about 18 mg, about 19 mg, about 20 mg, about 21 mg, about 22 mg, about 23 mg, about 24 mg, about 25 mg, about 26 mg, about 27 mg, about 28 mg, about 29 mg, about 30 mg, about 31 mg, about 32 mg, about 33 mg, about 34 mg, about 35 mg, about 36 mg, about 37 mg, about 38 mg, about 39 mg, about 40 mg, about 41 mg, about 42 mg, about 43 mg, about 44 mg, about 45 mg, about 46 mg, about 47 mg, about 48 mg, about 49 mg or about 50 mg, preferably about 20 µg, about 60 µg, about 120 µg, about 360 µg, about 800 µg, about 1600 µg, about 3000 µg, about 3500 µg, about 4000 µg, about 4500 µg, about 5000 µg, about 5500 µg, or about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg, about 15 mg, about 16 mg, about 17 mg, about 18 mg, about 19 mg or about 20 mg, more preferably about 1600 µg, about 3000 µg, about 4000 µg, about 5000 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg or about 15 mg. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 1000 µg, about 1200 µg, about 1800 µg, about 2000 µg or about 2500 µg, or about 1000 µg to about 2500 µg or about 1200 µg to about 2500 µg and an an�gen- binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 1600 µg, about 3000 µg, about 4000 µg, about 5000 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg or about 15 mg or about 1600 µg to about 5000 µg, about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg, about 12 mg to about 20 mg, about 20 mg to about 30 mg or about 30 mg to about 50 mg, preferably about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg or about 12 mg to about 20 mg. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 1000 µg, about 1200 µg, about 1800 µg, about 2000 µg or about 2500 µg, or about 1000 µg to about 2500 µg, about 1000 µg to about 4000 µg or about 1200 µg to about 2500 µg and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 1600 µg, about 3000 µg, about 4000 µg, about 5000 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg or about 15 mg or about 1600 µg to about 5000 µg, about 3000 µg to about 8000 µg, about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg, about 12 mg to about 20 mg, about 20 mg to about 30 mg or about 30 mg to about 50 mg, preferably about 3000 µg to about 8000 µg, about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg or about 12 mg to about 20 mg. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 1000 µg, about 1200 µg, about 1800 µg, about 2000 µg or about 2500 µg, or about 1000 µg to about 2500 µg, about 1000 µg to about 4000 µg or about 1200 µg to about 2500 µg and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 1600 µg, about 3000 µg, about 4000 µg, about 5000 µg, about 6000 µg, about 7000 µg, about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg or about 15 mg or about 1600 µg to about 5000 µg, about 3000 µg to about 8000 µg, about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg, about 12 mg to about 20 mg, about 20 mg to about 30 mg or about 30 mg to about 50 mg, preferably about 3000 µg to about 8000 µg, about 5000 µg to about 8000 µg, about 8000 µg to about 12 mg or about 12 mg to about 20 mg. Also the concentra�ons used in the in vitro assay of Example 4 can be used to es�mate the doses that may be used for the combina�on of the MAG-003 TCER® and the PRAME-004 TCER®. Doses can be calculated using the molecular weight of the respec�ve TCER® molecule derived from the amino acid sequence and the assump�on that ~10% of the Cmaxpa�ent plasma or serum TCER® concentra�on corresponds to the expected TCER® concentra�on at the tumor site. Cmaxvalues may be derived from EP24174662.7, EP24199013.4, EP25151617.5, EP24213284.3 and EP25166821.6. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 0.34 µg to about 34 mg, such as about 0.34 µg, about 3.4 µg, about 34 µg, about 340 µg, about 3400 µg or about 34 mg and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 0.38 µg to about 38 mg, such as about 0.38 µg, about 3.8 µg, about 38 µg, about 380 µg, about 3800 µg or about 38 mg. The inven�on also relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof (a combina�on of) an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76 at a dose of about 34 µg to about 3400 µg, such as about 34 µg, about 340 µg or about 3400 µg and an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72 at a dose of about 380 µg to about 38 mg, such as about 380 µg, about 3800 µg, about 30 mg or about 38 mg. Step dosing of the an�gen-binding proteins may be performed as described in EP24174662.7, EP24199013.4, EP25151617.5, EP24213284.3 and EP25166821.6 which are incorporated herein by reference in its en�rety. The inven�on relates to a method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein the treatment comprises administra�on to the pa�ent a) at least onefirst dose of about 200 µg to about 1000 µg, such as 300 µg; b) at least one second dose of about 400 µg to about 1000 µg, such as about 600 µg; c) at least one third dose in the range of about 600 µg to about 6000 µg, such as about 1000 µg, about 1100 µg, about 1200 µg, about 1300 µg, about 1400 µg, about 1500 µg about 1600 µg, about 1700 µg, about 1800 µg, about 1900 µg, about 2000 µg, about 2100 µg, about 2200 µg, about 2300 µg, about 2400 µg, about 2500 µg, about 2600 µg, about 2700 µg, about 2800 µg, about 2900 µg, about 3000 µg, about 3100 µg, about 3200 µg, about 3300 µg, about 3400 µg, about 3500 µg, about 3600 µg, about 3700 µg, about 3800 µg, about 3900 µg, about 4000 µg, about 4100 µg, about 4200 µg, about 4300 µg, about 4400 µg, about 4500 µg, about 4600 µg, about 4700 µg, about 4800 µg, about 4900 µg, about 5000 µg, about 5100 µg, about 5200 µg, about 5300 µg, about 5400 µg, about 5500 µg, about 5600 µg, about 5700 µg, about 5800 µg, about 5900 µg or about 6000 µg or about 1000 µg to about 4000 µg, such as about 1000 µg to about 2500 µg or about 1200 µg to about 2500 µg of an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 79 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76; and a) at least onefirst dose in the range of about 40 µg to about 120 µg such as about 40 µg, about 50 µg, about 60 µg, about 70 µg or about 80 µg; b) at least one second dose in the range of about 120 µg to about 400 µg, such as about 120 µg, about 200 µg, about 300 µg or about 400 µg; c) op�onally at least one third dose in the range of about 400 µg to about 2000 µg, such as 1600 µg or 2000 µg; and d) at least one further dose in the range of about 2000 µg to about 6000 µg or about 6000 µg to about 30 mg, such as about 4000 µg, about 5000 µg or about 8000 µg, about 9000 µg, about 10 mg, about 11 mg, about 12 mg, about 13 mg, about 14 mg, about 15 mg, about 16 mg, about 17 mg, about 18 mg, about 19 mg or about 20 mg of an an�gen-binding protein comprising a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 74 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72. The described an�gen-binding proteins may be administered intravenously. The subject or pa�ent to be treated is preferably human. As men�oned above, it is envisaged that in par�cular cancer is treated by the herein described an�gen-binding proteins, nucleic acids, vectors, host cells, uses and methods. The skilled person is readily capable to choose cancers that can be treated by the herein described means and methods. The cancer may also be selected from the group consis�ng of adrenocor�cal carcinoma, bladder cancer, preferably (urinary) bladder carcinoma or bladder urothelial carcinoma, brain tumor, in par�cular glioblastoma, primary brain cancer, or atypical meningioma, breast cancer, in par�cular triple-nega�ve breast cancer or breast carcinoma, cervical carcinoma, in par�cular cervical squamous cell carcinoma or endocervical adenocarcinoma, cholangiocellular carcinoma, colorectal cancer, in par�cular colon cancer, endometrial cancer, in par�cular uterine carcinoma or uterine carcinosarcoma, epithelial cancer of the larynx, esophageal cancer, preferably large cell neuroendocrine tumor of the esophagus, esophageal carcinoma or esophageal squamous cell carcinoma, gastroesophageal junc�on cancer (GEJC), fallopian tube cancer, gallbladder cancer, preferably gallbladder adenocarcinoma, gastro-intes�nal cancer, gastric cancer (GC), preferably gastric adenocarcinoma; colorectal cancer (CRC); pancrea�c cancer (PACA), germ cell tumor, head and neck cancer, in par�cular head and neck adenocarcinoma, head and neck squamous cell carcinoma or cervical squamous cell carcinoma, liver cancer, in par�cular hepatocellular cancer or hepatocellular carcinoma, leukemia, in par�cular acute myeloid leukemia or chronic lymphocy�c leukemia, lung cancer, in par�cular small cell lung cancer, non-small cell lung cancer, non-small cell lung adenocarcinoma, non-small cell lung squamous cell carcinoma (sqNSCLC), large cell neuroendocrine tumor of the lung or large cell carcinoma of the lung, lymphoma, in par�cular extranodal T / NK-cell lymphoma, non-Hodgkin lymphoma, or H. pylori-induced MALT non- Hodgkin lymphoma, malignant peripheral nerve sheath tumors, skin cancer, in par�cular melanoma, in par�cular amelano�c melanoma, uveal melanoma, mucosal melanoma or cutaneous melanoma, mesothelioma, oral cavity carcinomas, oral squamous carcinoma, ovarian cancer, in par�cular epithelial ovarian cancer, serous ovarian cancer, ovarian carcinoma or ovarian carcinosarcoma, ovarian serous carcinoma, epithelial ovarian, fallopian tube, and primary peritoneal cancers (EOFPC), papillary thyroid carcinoma, primary peritoneal cancer, in par�cular restricted to serous, clear cell, and endometrioid subtypes, prostate cancer, renal cancer, in par�cular renal carcinoma, in par�cular renal clear cell carcinoma, renal papillary cell carcinoma, salivary duct carcinoma, sarcoma, in par�cular Ewing's sarcoma, fibrosarcoma, liposarcoma, osteosarcoma, sarcoma of the tonsil or synovial sarcoma (spindle cell, biphasic, and poorly differen�ated subtypes), tes�cular cancer, in par�cular tes�cular germ cell tumor, thymoma, urothelial carcinoma, uterine cancer (UEC), preferably uterine carcinosarcoma or uterine carcinoma, Merkel cell carcinoma, Neuroendocrine neoplasms (NEN), preferably Neuroendocrine Tumor CUP, gallbladder cancer (GBC), preferably gallbladder adenocarcinoma and bile duct cancer (CCC). The cancer may also be selected from the group consis�ng of adrenocor�cal carcinoma, bladder cancer, brain tumor, in par�cular glioblastoma, primary brain cancer, or atypical meningioma, breast cancer, in par�cular triple-nega�ve breast cancer, cervical carcinoma, in par�cular cervical squamous cell carcinoma or endocervical adenocarcinoma, cholangiocellular carcinoma, colorectal cancer, in par�cular colon cancer, endometrial cancer, in par�cular uterine carcinosarcoma, epithelial cancer of the larynx, esophageal carcinoma, fallopian tube cancer, gallbladder cancer, gastro-intes�nal cancer, germ cell tumor, head and neck cancer, in par�cular head and neck adenocarcinoma, or head and neck squamous cell carcinoma, hepatocellular carcinoma, leukemia, in par�cular acute myeloid leukemia or chronic lymphocy�c leukemia, lung cancer, in par�cular small cell lung cancer, non-small cell lung cancer, non-small cell lung adenocarcinoma, non-small cell lung squamous cell carcinoma (sqNSCLC), lymphoma, in par�cular extranodal T / NK-cell lymphoma, non-Hodgkin lymphoma, or H. pylori-induced MALT non-Hodgkin lymphoma, malignant peripheral nerve sheath tumors, melanoma, in par�cular amelano�c melanoma, uveal melanoma, or cutaneous melanoma, mesothelioma, oral cavity carcinomas, oral squamous carcinoma, ovarian cancer, in par�cular epithelial ovarian cancer, serous ovarian cancer or ovarian carcinosarcoma, papillary thyroid carcinoma, primary peritoneal cancer, in par�cular restricted to serous, clear cell, and endometrioid subtypes, prostate cancer, renal carcinoma, in par�cular renal clear cell carcinoma, renal papillary cell carcinoma, salivary duct carcinoma, sarcoma, in par�cular Ewing's sarcoma,fibrosarcoma, liposarcoma, osteosarcoma, or synovial sarcoma, tes�cular cancer, in par�cular tes�cular germ cell tumor, thymoma, urothelial carcinoma and uterine carcinoma. The cancer may also be selected from the group consis�ng of lung cancer such as small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) or large cell lung cancer (LCLC), preferably non-small cell lung cancer adenocarcinoma (NSCLCadeno), squamous cell non- small cell lung cancer (NSCLCsquam) or large cell neuroendocrine tumor of the lung; liver cancer, preferably hepatocellular cancer (HCC); head and neck cancer, preferably head and neck squamous cell carcinoma (HNSCC) or cervical squamous cell carcinoma; skin cancer, preferably melanoma (MEL), preferably cutaneous melanoma or mucosal melanoma; renal cell cancer (RCC); brain cancer, preferably glioblastoma (GBM); gastric cancer (GC), preferably gastric adenocarcinoma; colorectal cancer (CRC); pancrea�c cancer (PACA); prostate cancer (PRAD); leukemia, preferably acute myeloid leukemia (AML) or chronic lymphocy�c leukemia (CLL); lymphoma, preferably non-Hodgkin lymphoma (NHL); breast cancer (BRCA), preferably triple-nega�ve breast cancer (TNBC); Merkel cell carcinoma; ovarian cancer (OC), preferably ovarian carcinoma or ovarian serous carcinoma; (urinary) bladder cancer (UBC), preferably (urinary) bladder carcinoma or bladder urothelial carcinoma; uterine cancer (UEC), preferably uterine carcinosarcoma; gallbladder cancer (GBC), preferably gallbladder adenocarcinoma; bile duct cancer (CCC); sarcoma (SARC), preferably synovial sarcoma, sarcoma of the tonsil or osteosarcoma; esophageal cancer, preferably large cell neuroendocrine tumor of the esophagus or esophageal squamous cell carcinoma; gastroesophageal junc�on cancer (GEJC); Neuroendocrine neoplasms (NEN), preferably ...

Claims

Claims 1. An an�gen-binding protein comprising two IgG CH3-containing polypep�des, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and the amino acid variant Y349C.

2. The an�gen-binding protein of claim 1, wherein (i) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 368 by aspar�c acid or glutamic acid and the amino acid variant S354C, andthe second polypep�de comprises the subs�tu�on of amino acids at posi�on 351 and at posi�on 366 by lysine, arginine or his�dine and the amino acid variant Y349C.

3. The an�gen-binding protein of claim 1 or 2, wherein (i) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant Y349C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant S354C; or (ii) thefirst polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by aspar�c acid and the subs�tu�on of the amino acid at posi�on 368 by glutamic acid and the amino acid variant S354C, and the second polypep�de comprises the subs�tu�on of the amino acid at posi�on 351 by lysine and the subs�tu�on of the amino acid at posi�on 366 by lysine and the amino acid variant Y349C.

4. The an�gen-binding protein of any one of claims 1 to 3, wherein thefirst and second polypep�de specifically bind to each other.

5. The an�gen-binding protein of any one of claims 1 to 4, wherein the amino acids subs�tuted in thefirst polypep�de interact with the subs�tuted amino acids in the second polypep�de.

6. The an�gen-binding protein of any one of claims 1 to 5, wherein the an�gen-binding protein is a bispecific, trispecific or mul�specific an�gen-binding protein, preferably a bispecific an�gen-binding protein.

7. The an�gen-binding protein of any one of claims 1 to 6, wherein the an�gen-binding protein comprises afirst binding domain and a second binding domain.

8. The an�gen-binding protein of claim 7, wherein thefirst binding domain specifically binds to a cell surface molecule of a human immune cell and / or the second binding domain specifically binds to an MHC-associated pep�de epitope.

9. The an�gen-binding protein of claim 7 or 8, wherein thefirst and / or second binding domain comprises or consists of (an) an�body(ies) or (a) func�onal fragment(s) or deriva�ve(s) thereof.

10. The an�gen-binding protein of any one of claims 7 to 9, wherein thefirst and / or second binding domain comprises or consists of (a) T cell receptor(s) (TCR) or (a) func�onal fragment(s) or deriva�ve(s) thereof.

11. The an�gen-binding protein of any one of claims 7 to 10, wherein thefirst binding domain comprises or consists of an an�body an�gen binding site (VD).

12. The an�gen-binding protein of any one of claims 7 to 11, wherein the second binding domain comprises or consists of a TCR an�gen binding site (VR).

13. The an�gen-binding protein of claim 11 or 12, wherein one polypep�de comprises the an�body variable light chain domain (VL) of the an�gen binding site (VD) and the other polypep�de comprises the an�body variable heavy chain domain (VH) of the an�gen binding site (VD).

14. The an�gen-binding protein of any one of claims 11 to 13, wherein one polypep�de comprises the TCR alpha variable domain (Vα) of the an�gen binding site (VR) and the other polypep�de comprises the TCR beta variable domain (Vβ) of the an�gen binding site (VR).

15. The an�gen-binding protein of claim 13 or 14, wherein one polypep�de comprises the an�body variable light chain domain (VL) and the TCR beta variable domain (Vβ) and the other polypep�de comprises the an�body variable heavy chain domain (VH) and the TCR alpha variable domain (Vα).

16. The an�gen-binding protein of claim 13 or 14, wherein one polypep�de comprises the an�body variable light chain domain (VL) and the TCR alpha variable domain (Vα) and the other polypep�de comprises the an�body variable heavy chain domain (VH) and the TCR beta variable domain (Vβ).

17. The an�gen-binding protein of any one of claims 1 to 16, wherein thefirst polypep�de further comprises a CH2 domain and / or the second polypep�de further comprises a CH2 domain.

18. The an�gen-binding protein of claim 17, wherein in one polypep�de the CH2 domain and the CH3 domain form a Fc domain FC1 and / or in the other polypep�de the CH2 domain and the CH3 domain form a Fc domain FC2.

19. The an�gen-binding protein of any one of claims 1 to 18, wherein thefirst polypep�de and the second polypep�de are on separate polypep�de chains or are connected by a linker.

20. The an�gen-binding protein of any one of claims 13 to 19, wherein thefirst polypep�de comprises a structure represented by the formula: V1-V2 [I]; and the second polypep�de comprises a structure represented by the formula: V3-V4 [II]; wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ;V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL.

21. The an�gen-binding protein of any one of claims 13 to 20, wherein the variable domains are connected by linkers.

22. The an�gen-binding protein of any one of claims 13 to 21, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2 [III]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4 [IV]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL.

23. The an�gen-binding protein of any one of claims 13 to 22, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-FC1 [V]; and the second polypep�de comprises a structure represented by the formula:V3-L2-V4-FC2 [VI]; wherein L1 and L2 are linkers and may be the same or different, wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL.

24. The an�gen-binding protein of any one of claims 13 to 23, wherein thefirst polypep�de comprises a structure represented by the formula: V1-L1-V2-L3-FC1 [VII]; and the second polypep�de comprises a structure represented by the formula: V3-L2-V4-L4-FC2 [VIII]; wherein L1, L2, L3 and L4 are linkers and may be the same or different, and wherein V1 is Vα, V2 is VH, V3 is VL, V4 is Vβ; V1 is VL, V2 is Vα, V3 is Vβ, V4 is VH; V1 is Vβ, V2 is VL, V3 is VH, V4 is Vα; V1 is VH, V2 is Vα, V3 is Vβ, V4 is VL; V1 is Vα, V2 is VL, V3 is VH, V4 is Vβ; V1 is VL, V2 is Vβ, V3 is Vα, V4 is VH; V1 is Vβ, V2 is VH, V3 is VL, V4 is Vα; or V1 is VH, V2 is Vβ, V3 is Vα, V4 is VL.

25. The an�gen-binding protein of any one of claims 21 to 24, wherein the linkers L1, L2, L3 and / or L4 comprise or consist of SEQ ID NO: 16 (GGGSGGGG).

26. The an�gen-binding protein of any one of claims 18 to 25, wherein FC1 and / or FC2 further comprise a hinge region, preferably wherein the hinge region comprises or consists of SEQ ID NO: 15 (EPKSS) or SEQ ID NO: 92 (EPKSC).

27. The an�gen-binding protein of any one of claim 18 to 26, wherein the FC1 and / or FC2 comprises at least one effector func�on silencing muta�on at a residue selected from posi�ons 233, 234, 235, 236, 297 and 331, preferably wherein said effector func�on silencing muta�on is generated by replacing at least one residue in posi�on 233, 234, 235, 236, and 331 with the corresponding residue derived from lgG2 or lgG4.

28. The an�gen-binding protein of any one of claims 18 to 27, wherein FC1 comprises or consists of the amino acid sequence according to SEQ ID NO: 1, 39, 88 or 90 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 39, 88 or 90; and / or FC2 comprises or consists of the amino acid sequence according to SEQ ID NO: 2, 40, 89 or 91 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 40, 89 or 91.

29. The an�gen-binding protein of any one of claims 13 to 28, wherein the an�body variable light chain domain (VL) and the an�body variable heavy chain domain (VH) associate to form a func�onal an�body an�gen binding site (VD).

30. The an�gen-binding protein of any one of claims 14 to 29, wherein the TCR alpha variable domain (Vα) and the TCR beta variable domain (Vβ) associate to form a func�onal TCR an�gen binding site (VR).

31. The an�gen-binding protein of any one of claim 8 to 30, wherein the cell surface molecule is known to induce the ac�va�on of the immune cell, or is at least one selected from the group consis�ng of immune response-related molecules, CD3, such as the CD3γ, CD3δ, and CD3ε chains, CD4, CD7, CD8, CD10, CD11b, CD11c, CD14, CD16, CD18,CD22, CD25, CD28, CD32a, CD32b, CD33, CD41 , CD41b, CD42a, CD42b, CD44, CD45RA, CD49, CD55, CD56, CD61, CD64, CD68, CD94, CD90, CD117, CD123, CD125, CD134, CD137, CD152, CD163, CD193, CD203c, CD235a, CD278, CD279, CD287, Nkp46, NKG2D, GITR, FcεRI, TCRa / β, TCRy / δ, and HLA-DR.

32. The an�gen-binding protein of any one of claim 8 to 31, wherein the cell surface molecule is a TCR / CD3 complex, preferably an alpha / beta TCR / CD3 complex.

33. The an�gen-binding protein of claim 32, wherein the an�gen-binding protein comprises: an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

34. The an�gen-binding protein of claim 32 or 33, wherein the an�gen-binding protein comprises: a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely.

35. The an�gen-binding protein of claim 32, wherein the an�gen-binding protein comprises: an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

36. The an�gen-binding protein of claim 32 or 35, wherein the an�gen-binding protein comprises: a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely.

37. The an�gen-binding protein of any one of claims 12 to 36, wherein the TCR an�gen binding site (VR) specifically binds to a bacterial pep�de, a viral pep�de or a tumor associated an�gen pep�de, preferably bound to a major histocompa�bility complex (MHC) protein.

38. A nucleic acid or separate nucleic acids encoding an an�gen-binding protein according to any one of the preceding claims.

39. A vector comprising the nucleic acid or the separate nucleic acids or separate vectors comprising the separate nucleic acids according to claim 38.

40. A host cell comprising the an�gen-binding protein, the nucleic acid or separate nucleic acids, or the vector or the separate vectors according to any one of the preceding claims.

41. A method for producing an an�gen-binding protein, wherein the method comprises (i) cul�va�ng the host cell of claim 40, (ii) producing the an�gen-binding protein, and op�onally (iii) harves�ng the host cell, and preferably (iv) isola�ng the an�gen-binding protein.

42. The protein as obtained or obtainable by claim 41.

43. A pharmaceu�cal composi�on comprising the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding claims or the an�gen binding protein as obtained by claim 42.

44. The pharmaceu�cal composi�on, the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding claims or the an�gen binding protein as obtained by claim 42 for use in medicine.

45. The pharmaceu�cal composi�on, the an�gen-binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, or the host cell according to any one of the preceding claims or the an�gen binding protein as obtained by claim 42 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders.

46. A method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the pharmaceu�cal composi�on, the an�gen- binding protein, the nucleic acid or separate nucleic acids, the vector or the separate vectors, the host cell according to any one of the preceding claims or the an�gen binding protein as obtained by claim 42 to a pa�ent in need thereof.

47. A method of muta�ng an an�gen-binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cystein, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cystein; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cystein, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein.

48. A method of increasing the heterodimerisa�on of an an�gen binding protein, wherein the an�gen-binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, andsubs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein.

49. A method of increasing the stability of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein.

50. A method of increasing the yield of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein.

51. A method of increasing the purity of an an�gen binding protein, wherein the an�gen- binding protein comprises two (human) IgG CH3-containing polypep�des, wherein the method comprises: (i) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine, and subs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine; or (ii) subs�tu�ng in thefirst polypep�de the amino acids at posi�on 351 and at posi�on 368 by a nega�vely charged amino acid and subs�tu�ng the amino acid at posi�on 354 by cysteine, andsubs�tu�ng in the second polypep�de the amino acids at posi�on 351 and at posi�on 366 by a posi�vely charged amino acid and subs�tu�ng the amino acid at posi�on 349 by cysteine; and op�onally isola�ng the an�gen binding protein.

52. A method for producing at least two different heteromeric an�gen-binding proteins in a single host cell, comprising (i) cul�va�ng the host cell, (ii) producing the an�gen-binding proteins, and op�onally (iii) harves�ng the host cell, and preferably (iv) isola�ng the an�gen-binding proteins, wherein the host cell comprises a nucleic acid encoding afirst an�gen-binding protein comprising at least one heteromeriza�on improving amino acid subs�tu�on and a nucleic acid encoding a second an�gen-binding protein comprising at least one heteromeriza�on improving subs�tu�on.

53. The method of claim 52, wherein the heteromeric an�gen-binding proteins are heterodimers and the heteromeriza�on improving amino acid subs�tu�ons are heterodimeriza�on improving amino acid subs�tu�ons.

54. The method of claim 53, wherein thefirst an�gen-binding protein is an an�gen-binding protein according to any one of the preceding claims.

55. The method of claim 54, wherein the heteromeriza�on improving amino acid subs�tu�ons of the second an�gen-binding protein are knob-into-hole amino acid subs�tu�ons or wherein the second an�gen-binding protein is an an�gen-binding protein according to any one of the preceding claims.

56. The method of claim 55, wherein the second an�gen-binding protein comprises two IgG CH3-containing polypep�des, wherein one polypep�de comprises the amino acidvariant T366W and the other polypeptide comprises the amino acid variant T366S, L368A and Y407V.

57. The method of claim 56, wherein of the second an�gen-binding protein one polypep�de further comprises the amino acid variant S354C and the other polypeptide further comprises the amino acid variant Y349C.

58. The method of claim 57, wherein the second an�gen-binding protein comprises one polypep�de comprising the amino acid sequence according to SEQ ID NO: 17 and another polypeptide comprising the amino acid sequence according to SEQ ID NO:

18.

59. The method of any one of claims 52 to 54, wherein the second an�gen-binding protein comprises one polypep�de comprising the sequence according to SEQ ID NO: 19 and another polypeptide comprising the amino acid sequence according to SEQ ID NO:

20.

60. The method of any one of claims 52 to 54, wherein the second an�gen-binding protein comprises one polypep�de comprising the sequence according to SEQ ID NO: 21 and another polypeptide comprising the amino acid sequence according to SEQ ID NO:

22.

61. The an�gen-binding proteins as obtained or obtainable by the method of any one of claims 52 to 60.

62. A pharmaceu�cal composi�on comprising at least two of the an�gen-binding proteins as defined in any one of the preceding claims.

63. A pharmaceu�cal composi�on comprising a nucleic acid or separate nucleic acids encoding at least two of the an�gen-binding proteins as defined in any one of the preceding claims.

64. The pharmaceu�cal composi�on of claim 62 or 63 for use in medicine.

65. The pharmaceu�cal composi�on of claim 64 for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders.

66. A method of treatment of a disease or disorder comprising administering a therapeu�cally effec�ve amount of the pharmaceu�cal composi�on of claim 62 or 63 to a pa�ent in need thereof.

67. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex(MHC) protein for use as medicine.

68. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders.

69. A combina�on comprising an an�gen-binding protein binding to MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen- binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

70. A pharmaceu�cal composi�on comprising an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

71. A pharmaceu�cal composi�on for use in a method of trea�ng a condi�on or disease by producing at least two an�gen-binding proteins in vivo, wherein the pharmaceu�cal composi�on comprises a nucleic acid or nucleic acids encoding at least two an�gen- binding proteins, wherein the method comprises contac�ng a cell,�ssue or organismwith the pharmaceu�cal composi�on and wherein one of the at least two an�gen- binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen- binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

72. An an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

73. An an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein for use in the treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders, wherein said an�gen-binding protein is administered in combina�on with an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein.

74. A method of protein produc�on in a cell popula�on, wherein the method comprises contac�ng a cell popula�on with a nucleic acid or nucleic acids encoding at least two an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids under condi�ons such that an effec�ve amount of the protein is produced in the cell popula�on, wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

75. A method for inducing in vivo transla�on of at least two an�gen-binding proteins in a subject in need thereof, comprising administering to the subject an effec�ve amount of a nucleic acid or nucleic acids encoding the at least two an�gen-binding proteins or a pharmaceu�cal composi�on comprising said nucleic acid or nucleic acids undercondi�ons such that the nucleic acid(s) is / are localized into a cell of the subject and the an�gen-binding proteins are capable of being translated in the cell from the nucleic acid(s), wherein one of the at least two an�gen-binding proteins binds to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and another of the at least two an�gen-binding proteins binds to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

76. A method of treatment of cancer, a tumor or tumorous disease or disorder, infec�ous diseases, or immunological disorders comprising administering to a subject in need thereof an an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and an an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) protein.

77. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 67 to 76, comprising one or more further an�gen- binding proteins.

78. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 67 to 77, wherein the an�gen-binding protein binding to a MAGEA4 / 8 derived pep�de bound to a major histocompa�bility complex (MHC) protein and the an�gen-binding protein binding to a PRAME derived pep�de bound to a major histocompa�bility complex (MHC) and op�onally one or more further an�gen-binding proteins act together to provide a desired therapeu�c effect.

79. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 67 to 78, wherein the MAGEA4 / 8 derived pep�de is a pep�de according to SEQ ID NO:

57.

80. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 67 to 79, wherein the PRAME derived pep�de is a pep�de according to SEQ ID NO: 58.

81. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 80, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 62, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 63, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 64; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 59, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 60, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 61, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

82. The an�gen binding proteins for use, the combina�on , the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 81, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 54 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 54 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 62, 63, and 64, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 53 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 53 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 59, 60, and 61, respec�vely.

83. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 82, wherein the an�gen-binding proteinbinding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises an an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 11, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

84. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 83, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 9 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 9 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 11, and 12, respec�vely.

85. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 84, wherein the an�gen-binding proteinbinding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises or consists of afirst polypep�de chain comprising a structure represented by the formula: VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different.

86. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of claim 85, wherein L1 and / or L2 comprise or consist of an amino acid sequence according to SEQ ID NO:

16.

87. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of claim 85 or 86, wherein FC1 comprises or consists of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 comprises or consists of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40.

88. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 79 to 87, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 57 bound to a major histocompa�bility complex (MHC) protein comprises a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 75, 79, 80 or 82 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 76, 81 or 83.

89. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 88, wherein the an�gen-binding proteinbinding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a T cell receptor (TCR) alpha variable domain (Vα) and a TCR beta variable domain (Vβ), wherein the Vα domain comprises (i) a CDRα1 comprising the amino acid sequence according to SEQ ID NO: 68, (ii) a CDRα2 comprising the amino acid sequence according to SEQ ID NO: 69, and (iii) a CDRα3 comprising the amino acid sequence according to SEQ ID NO: 70; and wherein the Vβ domain comprises (i) a CDRβ1 comprising the amino acid sequence according to SEQ ID NO: 65, (ii) a CDRβ2 comprising the amino acid sequence according to SEQ ID NO: 66, and (iii) a CDRβ3 comprising the amino acid sequence according to SEQ ID NO: 67, wherein one or more of CDRα1, CDRα2, CDRα3, CDRβ1, CDRβ2 and CDRβ3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

90. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 89, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a Vα comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 56 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 56 and comprising the CDRα1, CDRα2, and CDRα3 according to SEQ ID NOs: 68, 69, and 70, respec�vely; and a Vβ comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 55 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 55 and comprising the CDRβ1, CDRβ2, and CDRβ3 according to SEQ ID NOs: 65, 66, and 67, respec�vely.

91. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 90, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprisesan an�body variable light chain domain (VL), and an an�body variable heavy chain domain (VH), wherein the VL comprises (i) a CDRL1 comprising the amino acid sequence according to SEQ ID NO: 6, (ii) a CDRL2 comprising the amino acid sequence according to SEQ ID NO: 7, and (iii) a CDRL3 comprising the amino acid sequence according to SEQ ID NO: 8; and wherein the VH comprises (i) a CDRH1 comprising the amino acid sequence according to SEQ ID NO: 10, (ii) a CDRH2 comprising the amino acid sequence according to SEQ ID NO: 14, and (iii) a CDRH3 comprising the amino acid sequence according to SEQ ID NO: 12; wherein one or more of CDRL1, CDRL2, CDRL3, CDRH1, CDRH2, and CDRH3 may comprise one, two or three amino acid muta�ons, wherein the muta�on may be a dele�on, an inser�on, or a subs�tu�on, preferably a conserva�ve subs�tu�on.

92. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 91, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a VL comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 5 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 5 and comprising the CDRL1, CDRL2, and CDRL3 according to SEQ ID NOs: 6, 7, and 8, respec�vely; and a VH comprising or consis�ng of the amino acid sequence according to SEQ ID NO: 13 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 13 and comprising the CDRH1, CDRH2, and CDRH3 according to SEQ ID NOs: 10, 14, and 12, respec�vely.

93. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 92, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises or consists of afirst polypep�de chain comprising a structure represented by the formula:VL-L1-Vβ-FC1; and a second polypep�de chain comprising a structure represented by the formula: Vα-L2-VH-FC2; wherein L1 and L2 are linkers and may be the same or different and FC1 and FC2 are Fc- domains and may be the same or different.

94. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of claim 93, wherein L1 and / or L2 comprise or consist of an amino acid sequence according to SEQ ID NO:

16.

95. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of claim 93 or 94, wherein FC1 comprises or consists of an amino acid sequence according to SEQ ID NOs: 1, 17, 19, 21 or 39 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 1, 17, 19, 21 or 39 and / or FC2 comprises or consists of an amino acid sequence according to SEQ ID NOs: 2, 18, 20, 22 or 40 or an amino acid sequence having at least 85%, 90%, 95%, 98% or 99% iden�ty to SEQ ID NO: 2, 18, 20, 22 or 40.

96. The an�gen binding proteins for use, the combina�on, the pharmaceu�cal composi�ons or the methods of any one of claims 80 to 95, wherein the an�gen-binding protein binding to the pep�de according to SEQ ID NO: 58 bound to a major histocompa�bility complex (MHC) protein comprises a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 71, 74, 84 or 86 and a polypep�de comprising or consis�ng of an amino acid sequence according to SEQ ID NOs: 72, 85 or 87.

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