IL-2 CONJUGATES AND METHODS OF USE THEREOF

Abstract

The present invention relates to an IL-2 conjugate comprising: an IL-2 polypeptide comprising a lysine analog comprising an azide group covalently linked to a conjugation moiety comprising a polyethylene glycol (PEG), wherein: the IL-2 polypeptide comprises an amino acid sequence having at least 80% sequence identity with SEQ ID NO: 1; and the lysine analog substitutes at least one amino acid residue within the IL-2 polypeptide at position K35, F42, F44, K43, E62, P65, R38, T41, E68, Y45, V69, L72 or Y107 with reference to the amino acid positions within SEQ ID NO: 1.

Description

The present application claims US provisional patent application no. 62 / 802,191, filed February 6, 2019; US provisional patent application no. 62 / 847,844, filed May 14, 2019; US provisional patent application no. 62 / 870,581, filed July 3, 2019; US provisional patent application no. 62 / 899,035, filed September 11, 2019 and U.S. Provisional Patent Application No. 62 / 940,173, filed November 25, 2019, all of which are incorporated by reference in their entirety. AczAnn / Lznz / E / Yii Background of the invention Different populations of T lymphocytes modulate the immune system to maintain immune homeostasis and tolerance. For example, regulatory T cells (Treg) prevent inappropriate responses by the immune system by preventing pathological reactivity itself while cytotoxic T cells target and destroy infected cells and / or cancer cells. In some instances, modulation of different populations of T lymphocytes provides an option for the treatment of a disease or indication. Brief description of the invention Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (I ): Formula (I); where: Y is CH2 and Z is RczRnn / Lznz / E / YiA ψ» or Y is CH2 and Z is0; W is a PEG group having a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa, and 60 kDa; and X has the structure: or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2e Y is Ψ'H OO , o a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Y is CH2 and Z is Ψ' H OR θ ,ο a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2e and Y is θθ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2e and Y is ψ»θθ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Y is CH2 and Z is ψ-Oθ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight selected from 5 kDa, 10 kDa, 20 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate. of the same. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 10 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 15 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 20 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 25 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 35 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 40 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 45 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 50 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 60 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is selected from K35, F42, F44, K43, E62, P65, R38, T41, E68, Y45, V69 and L72, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is selected from F42, E62, and P65, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof .In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is K35, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence. RczRnn / ίζηζ / Ε / γι of the IL-2 conjugate is F42, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is F44, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is K43, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is E62, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is P65, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is R38, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is T41, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is E68, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is Y45, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is V69, where the position RczRnn / ίζηζ / Ε / γι of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is L72, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 4 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (I ): RczRnn / ίζηζ / Ε / γι Formula (I); where: Z is CH2e Y is0 0 Z is CH2e Y is Y is CH2 and Z is W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2 and Y is OR θ,0 a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Y is CH2 and Z is Ψ'H θ θ,0 a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2 and Y is ψ»O \Nvv θ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Z is CH2 and Y is ψ* or θ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, Y is CH2 and Z is ψ, Oθ, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight selected from 5 kDa, 10 kDa, 20 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate. of the same. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 10 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 15 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 20 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 25 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has a molecular weight RczAnn / ίζηζ / Ε / γι average of 35 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 40 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 45 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 50 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG group has an average molecular weight of 60 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is selected from K35, F42, F44, K43, E62, P65, R38, T41, E68, Y45, V69 and L72, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is selected from F42, E62, and P65, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof . In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is K35, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is F42, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is F44, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is K43, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is E62, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in RczRnn / Lznz / E / Yi reference the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is P65, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is R38, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is T41, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is E68, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is Y45, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is V69, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is L72, where the position of the structure of the formula (I) in the amino acid sequence of the IL-2 conjugate is found in reference to the positions in SEQ ID NO: 1, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 15 to 19, wherein [AzK PEG] has the structure of formula (II) or formula (III), or a mixture of formula (II) and formula (III): RczRnn / ίζηζ / Ε / γι RczAnn / Lznz / E / YiA Formula (III); where: W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: X-1 j -·· ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK PEG] is a mixture of formula (II) and formula (III), or a pharmaceutically acceptable salt, solvate or hydrate of the same. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG] has the structure of formula (II): formula (II); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 15, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 16, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 17, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 18, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having a molecular weight RczRnn / Lznz / E / Yi average of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 19, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG] has the structure of formula (III) RczRnn / ίζηζ / Ε / γι formula (III); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 15, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having a selected average molecular weight of 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 16, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 17, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 18, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof.In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 19, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate of the. RczRnn / ίζηζ / Ε / γι itself. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear or branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG methoxy group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear or branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. An exemplary structure of a methoxy PEG group is illustrated in the mPEG-DBCO structure in Scheme 1 of Example 2. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK PEG] contains a PEG group that It has an average molecular weight of 5 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 10 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 15 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 20 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 25 kDa. In some modalities of a RczAnn / ίζηζ / Ε / γι IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group which has an average molecular weight of 30 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 35 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 40 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 45 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 50 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight of 60 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 15, 16, 17, 18 and 19, [AzK_PEG] contains a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa, where the PEG group is a methoxy PEG group, a linear methoxy PEG group, or a branched methoxy PEG group. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 20 to 24, wherein [AzK_PEG5kD] has the structure of formula (II) or formula (III), or a mixture of formula (II) and formula (III): RczRnn / ίζηζ / Ε / γι Formula (III); where: W is a PEG group having an average molecular weight of 5 kDa; and X has the structure: χ7ϊ) C^^ÍX+O ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 20, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 21, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 22, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 23, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 24, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG5kD] has the structure of formula (II) RczRnn / Lznz / E / YiAi formula (II); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 20, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 21, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 22, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 23, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 24, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG5kD] has the structure of formula (III) RczRnn / Lznz / E / Yii formula (III); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 20, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 21, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 22, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 23, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 24, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 25 to 29, wherein [AzK_PEG30kD] has the structure of formula (II) or formula (III), or is a mixture of the structures of formula (II) and formula (III): Formula (III); where: W is a PEG group having an average molecular weight of 30 kDa; and X has the structure: / \_NH ο^ηχ+ιΐί:; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 25, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 26, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 27, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 28, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 29, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG30kD] has the structure of formula (II): RczRnn / ίζηζ / Ε / γι formula (II); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 25, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 26, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 27, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 28, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 29, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_PEG30kD] has the structure of formula (III) RczRnn / Lznz / E / YiA formula (III); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 25, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 26, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 27, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 28, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 29, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 15 to 19, where [AzK_PEG] is a mixture of the structures of formula (II) and formula (III ): Formula (III); where: W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: X-IJ / \.NH c^^lx+i h ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK PEG] in the IL-2 conjugate is greater than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK PEG] in the IL-2 conjugate is less than 1:1. In some embodiments of an IL-2 conjugate described herein, W is a linear or branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG methoxy group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear or branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 20 to 24, where [AzK_PEG5kD] is a mixture of the structures of formula (II) and formula (III ): formula (II); RczRnn / Lznz / E / YiA RczRnn / Lznz / E / YiA Formula (III); where: W is a PEG group having an average molecular weight of 5 kDa; and X has the structure: X-1 / ^NH X+1 [: ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG5kD] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG5kD] in the IL-2 conjugate is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG5kD] in the IL-2 conjugate is less than 1:1. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 25 to 29, where [AzK_PEG30kD] is a mixture of the structures of formula (II) and formula (III ): Formula (III); where: W is a PEG group having an average molecular weight of 30 kDa; and X has the structure: χ7ϊ) ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG30kD] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG30kD] in the IL-2 conjugate is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (II) to the amount of the structure of formula (III) comprising the total amount of [ AzK_PEG30kD] in the IL-2 conjugate is less than 1:1. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 40 to 44, where [AzK_L1_PEG] has the structure of formula (IV) or formula (V), or a mixture of formula (IV) and formula (V): RczRnn / ίζηζ / Ε / γι formula (V); where: W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In RczRnn / Lznz / E / YiA some embodiments of an IL-2 conjugate described herein, [AzK_L1_PEG] is a mixture of formula (IV) and formula (V), or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the [AzK_L1_PEG] has the structure of formula (IV): formula (IV); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 40, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 41, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 42, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 43, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof.In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 44, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_L1_PEG] has the structure of formula (V). RczRnn / Lznz / E / Yii RczRnn / Lznz / E / YiA formula (V); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 40, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 41, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 42, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 43, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof.In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 44, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa and 30 kDa, or a salt, a solvate or a pharmaceutically acceptable hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight selected from 5 kDa and 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 5 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG group having an average molecular weight of 30 kDa, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear or branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG methoxy group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear or branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some modalities. RczRnn / ίζηζ / Ε / γι of an IL-2 conjugate described herein, the PEG methoxy group is branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41,42, 43 and 44, [AzK_L1_PEG] contains a PEG group having a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa, and 60 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 5 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 10 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 15 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41,42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 20 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 25 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 30 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41,42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 35 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 40 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 45 kDa in some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41,42, 43 and 44, [AzK_L1_PEG ] contains a PEG group having an average molecular weight of 50 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43 and 44, [AzK_L1_PEG] contains a PEG group having an average molecular weight of 60 kDa. In some embodiments of an IL-2 conjugate described herein having the amino acid sequence selected from any of SEQ ID NO: 40, 41, 42, 43, and 44, [AzK_L1_PEG] contains a PEG group that has a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 RCZRnn / L7R7 / E / YI kDa and 60 kDa, where the PEG group is a PEG methoxy group, a linear PEG methoxy group, or a branched PEG methoxy group. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 45-49, wherein [AzK_L1_PEG5kD] has the structure of Formula (IV) or Formula (V) or a mixture of Formula (IV) and Formula (V): RczRnn / ίζηζ / Ε / γι Formula (V); where: W is a PEG group having an average molecular weight of 5 kDa; and X has the structure: ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 45, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 46, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 47, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 48, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 49, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_L1_PEG5kD] has the structure of formula (IV) RczRnn / Lznz / E / YiA formula (IV); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 45, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 46, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 47, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 48, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 49, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_L1_PEG5kD] has the structure of formula (V) the formula (V); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 45, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 46, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 47, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 48, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 49, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 50 to 54, wherein [AzK_L1_PEG30kD] has the structure of formula (IV) or formula (V), or is a mixture of the structures of formula (IV) and formula (V): RczRnn / ίζηζ / Ε / γι Formula (V); where: W is a PEG group having an average molecular weight of 30 kDa; and X has the structure: ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 50, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 51, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 52, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 53, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 54, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the [AzK_L1_PEG30kD] has the structure of formula (IV): RczRnn / Lznz / E / YiA formula (IV); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 50, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 51, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 52, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 53, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 54, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, [AzK_L1_PEG30kD] has the structure of formula (V) the formula (V); or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 50, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 51, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 52, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 53, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 54, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 40-44, where [Azk_L1_PEG] is a mixture of the structures of formula (IV) and formula (V ): RczRnn / ίζηζ / Ε / γι Formula (V); where: W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: | x-11( / χ,ΝΗ Cn^lx+ih ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG] in the IL-2 conjugate is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG] in the IL-2 conjugate is less than 1:1. In some embodiments of an IL-2 conjugate described herein, W is a linear or branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a linear PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a branched PEG group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, W is a PEG methoxy group, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear or branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is linear, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the PEG methoxy group is branched, or a pharmaceutically acceptable salt, solvate or hydrate thereof. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 45 to 49, where [AzK_L1_PEG5kD] is a mixture of the structures of formula (IV) and formula (V ): RczRnn / ίζηζ / Ε / γι Formula (V); where: W is a PEG group having an average molecular weight of 5 kDa; and X has the structure: |x-i [ / \,NH ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_ PEG5kD] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG5kD] in the IL-2 conjugate is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG5kD] in the IL2 conjugate is less than 1:1. Described herein are IL-2 conjugates comprising the amino acid sequence of any of SEQ ID NO: 50-54, where [AzK_L1_PEG30kD] is a mixture of the structures of Formula (V); where: W is a PEG group having an average molecular weight of 30 kDa; and X has the structure: ; or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG30kD] in the IL-2 conjugate is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK_L1_PEG30kD] in the IL-2 conjugate is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (IV) to the amount of the structure of formula (V) comprising the total amount of [ AzK L1 PEG30kD] in the IL-2 conjugate is less than 1:1. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI ) or (Vil), or a mixture of (VI) and (Vil): formula (VI) formula (Vil) where: n is an integer in the range of about 2 to about 5000; and X has the structure: , or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VI) and (Vil) is in the range of about 5 to about 4,600, or about 10 to about 4,000, or about 20 to about 3,000, or about 100 to about 3,000, or about 100 to about 2,900, or about 150 to about 2,900, or about 125 to about 2,900, or from about 100 to about 2,500, or from about 100 to about 2,000, or from about 100 to about 1,900, or from about 100 to about 1,850, or from about 100 to about 1,750, or from about 100 to about 1,650, or from about 100 to about 1,500, or about 100 to about 1,400, or about 100 to about 1,300, or about 100 to about 1,250, or about 100 to about 1,150, or about 100 to about 1,100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or about 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 340 to about 795, or about 341 to about 682, or from about 568 to about 909, or from about 227 to about 1,500, or from about 225 to about 2,280, or from about 460 to about 2,160, or from about 460 to about 2,050, or from about 341 to about 1,820, or from about 341 to about 1710, or about 341 to about 1250, or about 225 to about 1250, or about 341 to about 1250, or about 341 to about 1136, or about 341 to about 1023, or about 341 to about 910, or about 341 to about 796, or about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or from about 114 to about 800, or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (VI) and (Vil) is an integer that is selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818,1819,1930, 1931, 1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955 , 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of the formula (VI) and (Vil) in the amino acid sequence of the IL2 conjugate is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is by reference to the positions in SEQ ID NO: 3. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34 , F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71.In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position F41. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position F43. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position E61. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure. RczRnn / ίζηζ / Ε / γι of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 It is located in position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position T40. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position V68. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VI), formula (Vil), or a mixture of formula (VI) and (Vil) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VI) to the amount of the structure of formula (Vil) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VI) to the amount of the structure of formula (Vil) comprising the total amount of the conjugate of IL-2 is greater than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VI) to the amount of the structure of formula (Vil) comprising the total amount of the conjugate of IL-2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI) or (Vil), or a mixture of (VI) and (Vil), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to about 1150, or from about 100 to about 1100, or from about 100 to about 1000, or from about 100 to approximately 900, or approximately 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or about 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or from about 454 to about 796, or RczRnn / Lznz / E / Yii from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or from about 227 to about 1500, or from about 225 to about 2280, or from about 460 to about 2160, or from about 460 to about 2050, or from about 341 to about 1820, or from about 341 to about 1710, or from about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or from about 114 to about 910, or from about 114 to about 800, or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VI) and (Vil) is an integer selected from 2, 5, 10, 11 ,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1 135, 1136, 1137 1249 932, 2044, 2045, 2046, 2158 , 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955, 3408, 3409, 3410,3976, 3977, 3978,4544,4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI) or (Vil), or a mixture of (VI) and (Vil), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in compounds of formula (VI) and (Vil) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (VI) or (Vil), or a mixture of (VI) and (Vil), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VI) and (Vil) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. RczRnn / ίζηζ / Ε / γι In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (VI) or (Vil), or a mixture of (VI) and (Vil), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of approximately 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (VI) and (Vil) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (VI) or (Vil), or a mixture of (VI) and (Vil), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of approximately 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (VI) and (Vil) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 wherein at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI ) or (Vil), or a mixture of (VI) and (Vil), where n is an integer such that the molecular weight of the PEG moiety is in the range of about 1000 Daltons to about 200,000 Daltons, or from about 2000 Daltons to about 150,000 Daltons, or from about 3000 Daltons to about 125,000 Daltons, or from about 4000 Daltons to about 100,000 Daltons, or from about 5000 Daltons to about 100,000 Daltons, or from about 6000 Daltons to about 90,000 Daltons, or from about 7000 Daltons to about 80,000 Daltons, or from about 8000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 65,000 Daltons, or from about 5000 Daltons to about 60,000 Daltons, or from about 5000 Daltons to about 50,000 Daltons, or from about 6000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 45,000 Daltons, or from about 7000 Daltons to about 40,000 Daltons, or of approximately 8000 RczRnn / ίζηζ / Ε / γι daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 50,000 Daltons, or from approximately 9000 Daltons to approximately 45,000 Daltons, or from approximately 9000 Daltons to approximately 40,000 Daltons, or from approximately 9000 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 30,000 Daltons, or from approximately 9500 Daltons to approximately 35,000 Daltons, or from approximately 9500 Daltons to approximately 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10,000 Daltons to approximately 45,000 Daltons, or from approximately 10,000 Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI ) or (Vil), or a mixture of (VI) and (Vil), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltones, approximately 100,000 Daltones , approximately 125,000 Daltones, approximately 150,000 Daltones, approximately 175,000 Daltones or approximately 200,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VI ) or (Vil), or a mixture of (VI) and (Vil), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. RczRnn / ίζηζ / Ε / γι Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII ) or (IX), or a mixture of (VIII) and (IX): RCZRnn / L7R7 / E / YI formula (IX) where: n is an integer in the range from about 2 to about 5000: and X has the structure: , or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VIII) and (IX) ranges from about 5 to about 4600, or from about 10 to about 4000. , or from about 20 to about 3000, or from about 100 to about 3000, or from about 100 to about 2900, or from about 150 to about 2900, or from about 125 to about 2900, or from about 100 to about 2500, or from about 100 to about 2000, or from about 100 to about 1900, or from about 100 to about 1850, or from about 100 to about 1750, or from about 100 to about 1650, or from about 100 to about 1500, or from about 100 to about 1400, or about 100 to about 1300, or about 100 to about 1250, or about 100 to about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450 , or from about 100 to about 350, or from about 100 to about 275, or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to about 1710, or about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or from about 114 to about 910, or from about 114 to about 800, or about 114 to about 690, or about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VIII) and (IX) is an integer that It is selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021 , 1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818,1819,1930, 1931 , 1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546 In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the amino acid sequence of the IL2 conjugate is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71, where the position of the structure of formula (I) in the sequence of amino acids of the IL-2 conjugate is in reference to the positions in SEQ ID NO: 3.In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position F41. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position F43. In some. RczRnn / ίζηζ / Ε / γι modalities of an IL-2 conjugate described herein, the structure position of formula (VIII), formula (IX), or a mixture of formula (VIII) and ( IX) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is found at position E61. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is found at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position T40. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position V68. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (VIII), formula (IX), or a mixture of formula (VIII) and (IX) in the sequence of amino acids of the IL-2 conjugate of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VIII) to the amount of the structure of formula (IX) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VIII) to the amount of the structure of formula (IX) comprising the total amount of the conjugate of IL-2 is greater than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (VIII) to the amount of the structure of formula (IX) comprising the total amount of the conjugate of IL-2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII) or (IX), or a mixture of (VIII) and (IX), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to RczRnn / ίζηζ / Ε / γι about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or about 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 340 to about 795, or about 341 to about 682, or about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to about 1710, or about 341 to about 1250, or from about 225 to about 1,250, or from about 341 to about 1,250, or from about 341 to about 1,136, or from about 341 to about 1,023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or about 114 to about 800, or about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (VIII) and (IX) is an integer selected from 2 , 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,102 2, 1023 , 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818, 1819,1930, 1931, 1932, 2044 , 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953,2954, 2955, 3408, 3409,3410,3976, 3977, 3978,4544 ,4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (VIII) or (IX), or a mixture of (VIII) and (IX), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in compounds of formula (VIII) and (IX) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. RczRnn / ίζηζ / Ε / γι In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (VIII) or (IX), or a mixture of (VIII) and (IX), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (VIII) and (IX) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII) or (IX), or a mixture of (VIII) and (IX), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VIII) and (IX) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII) or (IX), or a mixture of (VIII) and (IX), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VIII) and (IX) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII ) or (IX), or a mixture of (VIII) and (IX), where n is an integer such that the molecular weight of the PEG fraction is in the range of about 1000 Daltons to about 200,000 Daltons, or from approximately 2000 Daltons to approximately 150,000 Daltons, or from approximately 3000 Daltons to approximately 125,000 Daltons, or from approximately 4000 Daltons to approximately 100,000 Daltons, or from approximately 5000 RczRnn / ίζηζ / Ε / γι daltons to approximately 100,000 Daltons, or from approximately 6000 Daltons to approximately 90,000 Daltons, or from approximately 7000 Daltons to approximately 80,000 Daltons, or from approximately 8000 Daltons to approximately 70,000 Daltons, or from approximately 5000 Daltons to approximately 70,000 Daltons, or from approximately 5000 Daltons to approximately 65,000 Daltons, or from approximately 5000 Daltons to approximately 60,000 Daltons, or from approximately 5000 Daltons to approximately 50,000 Daltons, or from approximately 6000 Daltons to approximately 50,000 Daltons, or from approximately 7000 Daltons to approximately 50,000 Daltons, or from approximately 7000 Daltons to approximately 45,000 Daltons, or from approximately 7000 Daltons to approximately 40,000 Daltons, or from approximately 8000 Daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 50,000 Daltons, or from approximately 9000 Daltons to approximately 45,000 Daltons, or from approximately 9000 Daltons to approximately 40,000 Daltons, or from approximately 9000 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 30,000 Daltons, or from approximately 9500 Daltons to approximately 35,000 Daltons, or from approximately 9500 Daltons to approximately 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10,000 Daltons to approximately 45,000 Daltons, or from approximately 10,000 Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII ) or (IX), or a mixture of (VIII) and (IX), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltones, approximately 100,000 Daltones , approximately 125,000 Daltons, approximately RczRnn / Lznz / E / Yi; 150,000 Daltones, approximately 175,000 Daltones or approximately 200,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (VIII ) or (IX), or a mixture of (VIII) and (IX), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X ) or (XI), or a mixture of (X) and (XI): RczRnn / Lznz / E / Yii formula (XI) where: n is an integer in the range of about 2 to about 5000: and the wavy lines indicate covalent bonds with the amino acid residue within SEQ ID NO: 3 that are not replaced, or a salt, a solvate or a pharmaceutically hydrate acceptable of it. In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is racemic, is enriched in (R), is enriched in (S), is substantially (R), is substantially (S) , is (R) or is (S). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is racemic. In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is enriched in (R). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is enriched in (S). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is substantially (R). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is substantially (S). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is (R). In some embodiments, the stereochemistry of the chiral center within formula (X) and formula (XI) is (S). In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (X) and (XI) ranges from about 5 to about 4600, or from about 10 to about 4000. , or from about 20 to about 3000, or from about 100 to about 3000, or from about 100 to about 2900, or from about 150 to about 2900, or from about 125 to about 2900, or from about 100 to about 2500, or from about 100 to about 2000, or from about 100 to about 1900, or from about 100 to about 1850, or from about 100 to about 1750, or from about 100 to about 1650, or from about 100 to about 1500, or from about 100 to about 1400, or about 100 to about 1300, or about 100 to about 1250, or about 100 to about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450 , or from about 100 to about 350, or from about 100 to about 275, or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to about 1710, or about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or from about 114 to about 910, or from about 114 to about 800, or about 114 to about 690, or about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (X) and (XI) is an integer that is selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, RczRnn / ίζηζ / Ε / γι 340,341,454,455,568,569,680,681,682,794,795,796,908,909,910,1021,1022,1023,1135,1136,1137,1249,1250,1 251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818,1819,1930, 1931, 1932, 2044, 2045, 2046, 2158, 2159, 216 0, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate is selected from K34, F41, F43, K42, E61, P64, R37 , T40, E67, Y44, V68, and L71, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is in reference to the positions in SEQ ID NO: 3. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F41. In some embodiments of an IL2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the conjugate of IL-2 of SEQ ID NO: 3 is found at position F43. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E61. In some embodiments of an IL2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the conjugate of IL-2 of SEQ ID NO: 3 is found at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position T40. In some embodiments of an IL2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the conjugate of IL-2 of SEQ ID NO: 3 is found at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some RczRnn / ίζηζ / Ε / γι modalities of an IL-2 conjugate described herein, the structure position of the formula (X) and (XI) or a mixture of the formula (X) and (XI) In the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 it is located at position V68. In some embodiments of an IL2 conjugate described herein, the position of the structure of the formula (X) and (XI) or a mixture of the formula (X) and (XI) in the amino acid sequence of the conjugate of IL-2 of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (X) to the amount of the structure of formula (XI) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (X) to the amount of the structure of formula (XI) comprising the total amount of the conjugate of IL-2 is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (X) to the amount of the structure of formula (XI) comprising the total amount of the conjugate of IL-2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X) or (XI), or a mixture of (X) and (XI), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to about 1150, or from about 100 to about 1100, or from about 100 to about 1000, or from about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or from about 100 to about 350, or from about 100 to about 275, or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 340 to about 795, or about 341 to about 682, or about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to about 1710, or about 341 to about 1250 , or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or from about RczRnn / ίζηζ / Ε / γι 114 to about 910, or from about 114 to about 800, or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (VI) and (Vil) is an integer selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251,1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818, 1819,1930, 1931,1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839 , 2840, 2841,2953, 2954, 2955, 3408, 3409, 3410, 3976,3977, 3978, 4544,4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X) or (XI), or a mixture of (X) and (XI), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in the compounds of formula (X) and (XI) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 , 910, 1021,1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X) or (XI), or a mixture of (X) and (XI), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (X) and (XI) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X) or (XI), or a mixture of (X) and (XI), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of the formula (X) and (XI) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. RczRnn / ίζηζ / Ε / γι In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X) or (XI), or a mixture of (X) and (XI), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (X) and (XI) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is approximately 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X ) or (XI), or a mixture of (X) and (XI), where n is an integer such that the molecular weight of the PEG fraction is in the range of about 1000 Daltons to about 200,000 Daltons, or from about 2000 Daltons to about 150,000 Daltons, or from about 3000 Daltons to about 125,000 Daltons, or from about 4000 Daltons to about 100,000 Daltons, or from about 5000 Daltons to about 100,000 Daltons, or from about 6000 Daltons to about 90,000 Daltons, or from about 7000 Daltons to about 80,000 Daltons, or from about 8000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 65,000 Daltons, or from about 5000 Daltons to about 60,000 Daltons, or from about 5000 Daltons to about 50,000 Daltons, or from about 6000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 45,000 Daltons, or from about 7000 Daltons to about 40,000 Daltons, or from about 8000 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 35,000 Daltons, or from about 9000 Daltons to about 50,000 Daltons, or from about 9000 Daltons to about 45,000 Daltons, or from about 9000 Daltons to about 40,000 Daltons, or from about 9000 Daltons to about 35,000 Daltons, or from about 9000 Daltons to about 30,000 Daltons, or from about 9500 Daltons to about 35,000 Daltons, or from about 9500 Daltons to about 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10,000 Daltons to approximately 45,000 Daltons, or from approximately 10,000 Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 RCZRnn / L7R7 / E / YI Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons Colorblind. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X ) or (XI), or a mixture of (X) and (XI), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltons, approximately 100,000 Daltons , approximately 125,000 Daltons, approximately 150,000 Daltons, approximately 175,000 Daltons, or approximately 200,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (X ) or (XI), or a mixture of (X) and (XI), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII ) or (XIII), or a mixture of (XII) and (XIII): RczRnn / ίζηζ / Ε / γι formula (XII) formula (XIII) RczAnn / Lznz / E / YiAi where: n is an integer in the range of about 2 to about 5000: and the wavy lines indicate covalent bonds with the amino acid residue within SEQ ID NO: 3 that are not replaced, or a salt, a solvate or a pharmaceutically hydrate acceptable of it. In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is racemic, is enriched in (R), is enriched in (S), is substantially (R), is substantially (S) , is (R) or is (S). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is racemic. In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is enriched in (R). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is enriched in (S). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is substantially (R). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is substantially (S). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is (R). In some embodiments, the stereochemistry of the chiral center within formula (XII) and formula (XIII) is (S). In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XII) and (XIII) is in the range of about 5 to about 4600, or from about 10 to about 4000. , or from about 20 to about 3000, or from about 100 to about 3000, or from about 100 to about 2900, or from about 150 to about 2900, or from about 125 to about 2900, or from about 100 to about 2500, or from about 100 to about 2000, or from about 100 to about 1900, or from about 100 to about 1850, or from about 100 to about 1750, or from about 100 to about 1650, or from about 100 to about 1500, or from about 100 to about 1400, or about 100 to about 1300, or about 100 to about 1250, or about 100 to about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450 , or approximately 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or from about 227 to about 1500, or from about 225 to about 2280, or from about 460 to about 2160, or from about 460 to about 2050, or from about 341 to about 1820, or from about 341 to about 1710, or from about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or about 114 to about 800, or about 114 to about 690, or about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XII) and (XIII) is an integer selected from 2 , 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 10 22, 1023 , 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818,1819,1930, 1931, 1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula ( XII) and (XIII) or a mixture of thephormula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is in reference to the positions in SEQ ID NO: 3. In some embodiments of an IL-2 conjugate IL-2 described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F41. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID RczRnn / ίζηζ / Ε / γι NO: 3 is located in position F43. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E61. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position T40. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position V68. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XII) and (XIII) or a mixture of the formula (XII) and (XIII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XII) to the amount of the structure of formula (XIII) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XII) to the amount of the structure of formula (XIII) comprising the total amount of the conjugate of IL-2 is greater than 1:1. In some embodiments of an IL2 conjugate described herein, the ratio of the amount of the structure of formula (XII) to the amount of the structure of formula (XIII) comprising the total amount of the IL conjugate -2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII) or (XIII), or a mixture of (XII) and (XIII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to RczRnn / ίζηζ / Ε / γι about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or about 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or from about 227 to about 1500, or from about 225 to about 2280, or from about 460 to about 2160, or from about 460 to about 2050, or from about 341 to about 1820, or from about 341 to about 1710, or from about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or about 114 to about 800, or about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of the formula (XII) and (XIII) is an integer that is selected from 2 ,5,10,11,22,23,113,114,227,228,340,341,454,455,568,569,680,681,682,794,795,796,908,909,910,1021,10 22, 1023 , 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818, 1819,1930, 1931, 1932, 2044 , 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953,2954, 2955, 3408, 3409,3410,3976, 3977, 3978,4544 ,4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII) or (XIII), or a mixture of (XII) and (XIII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in the compounds of formula (XII) and (XIII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. RczRnn / ίζηζ / Ε / γι In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII) or (XIII), or a mixture of (XII) and (XIII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of the formula (XII) and (XIII) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (XII) or (XIII), or a mixture of (XII) and (XIII), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (XII) and (XIII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of formula (XII) or (XIII), or a mixture of (XII) and (XIII), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in compounds of formula (XII) and (XIII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 wherein at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII ) or (XIII), or a mixture of (XII) and (XIII), where n is an integer such that the molecular weight of the PEG fraction is in the range of about 1000 Daltons to about 200,000 Daltons, or from approximately 2000 Daltons to approximately 150,000 Daltons, or from approximately 3000 Daltons to approximately 125,000 Daltons, or from approximately 4000 Daltons to approximately 100,000 Daltons, or from approximately 5000 RczRnn / ίζηζ / Ε / γι daltons to approximately 100,000 Daltons, or from approximately 6000 Daltons to approximately 90,000 Daltons, or from approximately 7000 Daltons to approximately 80,000 Daltons, or from approximately 8000 Daltons to approximately 70,000 Daltons, or from approximately 5000 Daltons to approximately 70,000 Daltons, or from approximately 5000 Daltons to approximately 65,000 Daltons, or from approximately 5000 Daltons to approximately 60,000 Daltons, or from approximately 5000 Daltons to approximately 50,000 Daltons, or from approximately 6000 Daltons to approximately 50,000 Daltons, or from approximately 7000 Daltons to approximately 50,000 Daltons, or from approximately 7000 Daltons to approximately 45,000 Daltons, or from approximately 7000 Daltons to approximately 40,000 Daltons, or from approximately 8000 Daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 40,000 Daltons, or from approximately 8500 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 50,000 Daltons, or from approximately 9000 Daltons to approximately 45,000 Daltons, or from approximately 9000 Daltons to approximately 40,000 Daltons, or from approximately 9000 Daltons to approximately 35,000 Daltons, or from approximately 9000 Daltons to approximately 30,000 Daltons, or from approximately 9500 Daltons to approximately 35,000 Daltons, or from approximately 9500 Daltons to approximately 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10,000 Daltons to approximately 45,000 Daltons, or from approximately 10,000 Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII ) or (XIII), or a mixture of (XII) and (XIII), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltones, approximately 100,000 Daltones , approximately 125,000 Daltons, approximately RczRnn / Lznz / E / Yii 150,000 Daltones, approximately 175,000 Daltones or approximately 200,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XII ) or (XIII), or a mixture of (XII) and (XIII), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 wherein at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV ) or (XV), or a mixture of (XIV) and (XV): RczRnn / ίζηζ / Ε / γι where: m is an integer from 0 to 20; p is an integer from 0 to 20; n is an integer in the range of about 2 to about 5000; and wavy lines indicate covalent bonds to amino acid residues within SEQ ID NO: 3 that are not replaced, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is racemic, is (R-enriched), (S-enriched), is substantially (R), is substantially (S) , is (R) or is (S). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is racemic. In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is enriched in (R). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is enriched in (S). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is substantially (R). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is substantially (S). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is (R). In some embodiments, the stereochemistry of the chiral center within formula (XIV) and formula (XV) is (S). In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is from 0 to 20, or from 0 to 18, or from 0 to 16, or from 0 to 14, or from 0 to 12, or from 0 to 10, or from 0 to 9, or from 0 to 8, or from 0 to 7, or from 0 to 6, or from 0 to 5, or from 0 to 4, or 0 to 3, or 0 to 2. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 0. In In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 1. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and (XV) is 2. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and (XV) is 3 In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 4. In some embodiments of an IL-2 conjugate described herein present, m in the compounds of the formula (XIV) and (XV) is 5. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and (XV) is 6. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 7. In some embodiments of an IL-2 conjugate described herein herein, m in the compounds of the formula (XIV) and (XV) is 8. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and ( XV) is 9. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 10. In some embodiments of an IL-2 conjugate that described herein, m in the compounds of the formula (XIV) and (XV) is 11. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and (XV) is 12. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 13. In some embodiments of an IL-2 conjugate 2 described herein, m in the compounds of the formula (XIV) and (XV) is 14. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula ( XIV) and (XV) is 15. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 16. In some embodiments of a IL-2 described herein, m in the compounds of formula (XIV) and (XV) is 17. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XIV) and (XV) is 18. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 19. In some embodiments of a IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 20. RczRnn / ίζηζ / Ε / γι In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is from 0 to 20, or from 0 to 18, or from 0 to 16, or from 0 to 14, or from 0 to 12, or from 0 to 10, or from 0 to 9, or from 0 to 8, or from 0 to 7, or from 0 to 6, or from 0 to 5, or from 0 to 4, or from 0 to 3, or from 0 to 2. In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 0. In In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 1. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and (XV) is 2. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and (XV) is 3 In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 4. In some embodiments of an IL-2 conjugate described herein present, p in the compounds of the formula (XIV) and (XV) is 5. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and (XV) is 6. In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 7. In some embodiments of an IL-2 conjugate described herein herein, p in the compounds of the formula (XIV) and (XV) is 8. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and ( XV) is 9. In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 10. In some embodiments of an IL-2 conjugate that As described herein, p in the compounds of the formula (XIV) and (XV) is 11. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and (XV) is 12. In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 13. In some embodiments of an IL-2 conjugate 2 described herein, p in the compounds of the formula (XIV) and (XV) is 14. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula ( XIV) and (XV) is 15. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XIV) and (XV) is 16. In some embodiments of a IL-2 described herein, p in the compounds of formula (XIV) and (XV) is 17. In some embodiments of an IL-2 conjugate described herein, p in the compounds of the formula (XIV) and (XV) is 18. In some embodiments of an IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 19. In some embodiments of a IL-2 conjugate described herein, p in the compounds of formula (XIV) and (XV) is 20. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XIV) and (XV) ranges from about 5 to about 4600, or from about 10 to about 4000. , or from about 20 to about 3000, or from about 100 to about 3000, or from about 100 to about 2900, or from about 150 to about 2900, or from about 125 to about 2900, or from about 100 to about 2500, or from about 100 to about 2000, or from about 100 to about 1900, or from about 100 to about 1850, or from about 100 to about 1750, or RczRnn / Lznz / E / Yi; from about 100 to about 1650, or from about 100 to about 1500, or from about 100 to about 1400, or from about 100 to about 1300, or from about 100 to about 1250, or from about 100 to about 1150, or from about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450, or about 100 to about 350, or about 100 to about 275, or about 100 to about 230, or about 150 to about 475, or about 150 to about 340, or about 113 to about 340, or about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or from about 227 to about 1500, or from about 225 to about 2280, or from about 460 to about 2160, or from about 460 to about 2050, or from about 341 to about 1820, or from about 341 to about 1710, or from about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or about 114 to about 800, or about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is an integer from 0 to 6, p is an integer from 0 to 6, and n is an integer selected from 113,114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1 135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is an integer from 1 to 6, p is an integer from 1 to 6, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is an integer from 2 to 6, p is an integer from 2 to 6, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is a an integer from 2 to 4, p is an integer from 2 to 4, and n is an integer that is selected from RczRnn / Lznz / B / Yi and 1137. In some modalities of a IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 1, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. what is described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568 , 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. the compounds of the formula (XIV) and (XV), m is 3, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of the formula (XIV) and (XV), m is 4, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795 , 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV) , m is 5, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 6, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 102 3 , 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 7, p is 2, and n is an integer. which is selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910,1021,1022,1023,1135,1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 8, p is 2, and n is an integer selected from 113, 114 , 227, 228, 340, 341,454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some modalities of a IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 9, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some modalities of a conjugate of IL-2 described herein in the compounds of formula (XIV) and (XV), m is 10, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455 In some embodiments, an IL-2 conjugate is described herein. the compounds of the formula (XIV) and (XV), m is 11, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of the formula (XIV ) and (XV), m is 11, p is 2, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681, 682, 794, 795 , 796, 908, 909, 910, 1021, 1022, RczRnn / ίζηζ / Ε / γι 1023,1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is a number integer that is selected from 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XIV) and (XV) is an integer selected from 2, 5, 10, 11, 22, 23 ,113,114,227,228,340,341,454,455,568,569,680,681,682,794,795,796,908,909,910,1021,1022,1023,1135 136, 1137, 1249 , 1250, 1251,1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818, 1819,1930, 1931,1932, 20 44, 2045, 2046, 2158, 2159 , 2160, 2271,2272, 2273, 2839, 2840, 2841,2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. In some modalities of a conjugate do of IL-2 that As described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is in reference to the positions in SEQ ID NO: 3. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F41. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F43. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E61. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is RczRnn / ίζηζ / Ε / γι is located in position T40. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position V68. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XIV) and (XV) or a mixture of the formula (XIV) and (XV) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XIV) to the amount of the structure of formula (XV) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XIV) to the amount of the structure of formula (XV) comprising the total amount of the conjugate of IL-2 is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XIV) to the amount of the structure of formula (XV) comprising the total amount of the conjugate of IL-2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to about 1150, or from about 100 to about 1100, or from about 100 to about 1000, or from about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450 , or from about 100 to about 350, or from about 100 to about 275, or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to RczRnn / ίζηζ / Ε / γι about 1710, or about 341 to about 1250, or about 225 to about 1250, or about 341 to about 1250, or about 341 to about 1136, or about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or about 114 to about 910, or from about 114 to about 800, or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XIV) and (XV) is an integer which is selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682 , 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818,1819,1930, 1931, 1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in the compounds of formula (XIV) and (XV) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XIV) and (XV) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of approximately 450 to approximately 800, or from approximately 454 to RczRnn / ίζηζ / Ε / γι about 796, or about 454 to about 682, or about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of the formula (XIV) and (XV) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is approximately 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XIV) and (XV) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV ) or (XV), or a mixture of (XIV) and (XV), where n is an integer such that the molecular weight of the PEG fraction is in the range of about 1000 Daltons to about 200,000 Daltons, or from about 2000 Daltons to about 150,000 Daltons, or from about 3000 Daltons to about 125,000 Daltons, or from about 4000 Daltons to about 100,000 Daltons, or from about 5000 Daltons to about 100,000 Daltons, or from about 6000 Daltons to about 90,000 Daltons, or from about 7000 Daltons to about 80,000 Daltons, or from about 8000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 65,000 Daltons, or from about 5000 Daltons to about 60,000 Daltons, or from about 5000 Daltons to about 50,000 Daltons, or from about 6000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 45,000 Daltons, or from about 7000 Daltons to about 40,000 Daltons, or from about 8000 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 35,000 Daltons, or from about 9000 Daltons to about 50,000 Daltons, or from about 9000 Daltons to about 45,000 Daltons, or from approximately 9,000 Daltons to approximately 40,000 Daltons, or from approximately 9,000 Daltons to approximately 35,000 Daltons, or from RczRnn / ίζηζ / Ε / γι approximately 9000 Daltons to approximately 30,000 Daltons, or from approximately 9500 Daltons to approximately 35,000 Daltons, or from approximately 9500 Daltons to approximately 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10.0 00 daltons to approximately 45,000 Daltons, or from approximately 10,000 Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV ) or (XV), or a mixture of (XIV) and (XV), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltones, approximately 100,000 Daltones , approximately 125,000 Daltones, approximately 150,000 Daltones, approximately 175,000 Daltones or approximately 200,000 Daltones. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV ) or (XV), or a mixture of (XIV) and (XV), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61 and P64 , m is an integer from 0 to 6, p is an integer from 0 to 6, and n is an integer RczRnn / ίζηζ / Ε / γι from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate that is described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795 , 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where m is a integer from 0 to 6, p is an integer from 0 to 6, and n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to approximately 909. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is an integer that is selected from 454, 455, 568, 569, 680, 681,682,794, 795,796,908,909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where m is an integer of 0 to 6, p is an integer from 0 to 6, and n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. In some modalities, n is approximately 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XIV) or (XV), or a mixture of (XIV) and (XV), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where m is an integer of 0 to 6, p is an integer from 0 to 6, and n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XIV) and (XV), m is 2, p is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is from about 550 to about 800. RczRnn / ίζηζ / Ε / γι In some embodiments, n is approximately 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced RczRnn / ίζηζ / Ε / γι by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII): formula (XVII) where: m is an integer from 0 to 20; n is an integer in the range of about 2 to about 5000; and wavy lines indicate covalent bonds to amino acid residues within SEQ ID NO: 3 that are not replaced, or a pharmaceutically acceptable salt, solvate or hydrate thereof. In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is racemic, is enriched in (R), is enriched in (S), is substantially (R), is substantially (S) , is (R) or is (S). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is racemic. In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is enriched in (R). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is enriched in (S). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is substantially (R). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is substantially (S). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is (R). In some embodiments, the stereochemistry of the chiral center within formula (XVI) and formula (XVII) is (S). In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is from 0 to 20, or from 0 to 18, or from 0 to 16, or from 0 to 14, or from 0 to 12, or from 0 to 10, or from 0 to 9, or from 0 to 8, or from 0 to 7, or from 0 to 6, or from 0 to 5, or from 0 to 4, or 0 to 3, or 0 to 2. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 0. In In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 1. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and (XVII) is 2. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and (XVII) is 3 In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 4. In some embodiments of an IL-2 conjugate described herein present, m in the compounds of the formula (XVI) and (XVII) is 5. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and (XVII) is 6. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 7. In some embodiments of an IL-2 conjugate described herein herein, m in the compounds of the formula (XVI) and (XVII) is 8. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and ( XVII) is 9. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 10. In some embodiments of an IL-2 conjugate that As described herein, m in the compounds of the formula (XVI) and (XVII) is 11. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and (XVII) is 12. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 13. In some embodiments of an IL-2 conjugate 2 described herein, m in the compounds of the formula (XVI) and (XVII) is 14. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula ( XVI) and (XVII) is 15. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 16. In some embodiments of an IL-2 conjugate IL-2 described herein, m in the compounds of formula (XVI) and (XVII) is 17. In some embodiments of an IL-2 conjugate described herein, m in the compounds of the formula (XVI) and (XVII) is 18. In some embodiments of an IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 19. In some embodiments of a IL-2 conjugate described herein, m in the compounds of formula (XVI) and (XVII) is 20. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XVI) and (XVII) is in the range of about 5 to about 4600, or from about 10 to about 4000. , or from about 20 to about 3000, or from about 100 to about 3000, or from about 100 to about 2900, or from about 150 to about 2900, or from about 125 to about 2900, or from about 100 to about 2500, or from about 100 to about 2000, or from about 100 to about 1900, or from about 100 to about 1850, or from about 100 to about 1750, or from about 100 to about 1650, or from about 100 to about 1500, or from about 100 to about 1400, or about 100 to about 1300, or about 100 to about 1250, or about 100 RCZRnn / L7R7 / E / YI at about 1150, or about 100 to about 1100, or about 100 to about 1000, or about 100 to about 900, or about 100 to about 750, or about 100 to about 700 , or from about 100 to about 600, or from about 100 to about 575, or from about 100 to about 500, or from about 100 to about 450, or from about 100 to about 350, or from about 100 to about 275 , or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or from about 454 to about 796, or about 454 to about 682, or about 340 to about 795, or about 341 to about 682, or about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or from about 460 to about 2050, or from about 341 to about 1820, or from about 341 to about 1710, or from about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or from about 341 to about 682, or from about 341 to about 568, or from about 114 to about 1000, or from about 114 to about 950, or from about 114 to about 910, or from about 114 to about 800, or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is an integer from 0 to 6, and n is an integer selected from 113 , 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1 137. In some modalities of a IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is an integer from 1 to 6, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of a con played from IL -2 described herein in the compounds of formula (XVI) and (XVII), m is an integer from 2 to 6, and n is an integer selected from 113, 114, 227, 228, 340 In some embodiments, an IL-2 conjugate is described herein. the compounds of the formula (XVI) and (XVII), m is an integer from 2 to 4, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, In some embodiments of an IL-2 conjugate described herein in the compounds of the formula (XVI) and (XVII), m is 1, and n is an integer which is selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795 , 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In RczRnn / ίζηζ / Ε / γι some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 2, and n is an integer selected from 113 , 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1 137. In some modalities of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 3, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. described herein in the compounds of the formula (XVI) and (XVII), m is 4, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569 , 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136, and 1137. formula (XVI) and (XVII), m is 5, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 6, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021 ,1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of the formula (XVI) and (XVII), m is 7, and n is an integer which is selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 8, and n is an integer selected from 113, 114, 227 , 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some embodiments of a conjugate of IL-2 described herein in the compounds of formula (XVI) and (XVII), m is 9, and n is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In the compounds of formula (XVI) and (XVII), m is 10, and π is an integer selected from 113, 114, 227, 228, 340, 341, 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of the formula (XVI) and (XVII), m is 11, and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 12 , and n is an integer selected from 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 102 3, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 2, and n is an integer selected from 680 , 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136 and 1137. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XVI) and (XVII) is an integer selected from 2, 5, 10, 11, 22, 23 , RczRnn / ίζηζ / Ε / γι 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021,1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251,1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 1704, 1705, 1817, 1818, 1819,1930, 1931,1932, 2044, 2045 , 2046, 2158, 2159, 2160, 2271, 2272, 2273, 2839, 2840, 2841,2953, 2954, 2955, 3408, 3409, 3410, 3976, 3977, 3978, 4544, 4545 and 4546. describes in Herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate is selected from K34, F41, F43 , K42, E61, P64, R37, T40, E67, Y44, V68 and L71, where the position of the structure of formula (I) in the amino acid sequence of the IL-2 conjugate is in reference to the positions in the SEQ ID NO: 3. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII ) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is selected from K34, F41, F43, K42, E61, P64, R37, T40, E67, Y44, V68 and L71. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K34. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F41. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is found at position F43. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position K42. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E61. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position P64. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position R37. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (XVI) and (XVII) or a mixture of formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position T40. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (XVI) and (XVII) or a mixture of formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position E67. In some embodiments of an IL-2 conjugate described herein, the position of the structure of formula (XVI) and (XVII) or a mixture of formula (XVI) and RczRnn / ίζηζ / Ε / γι (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position Y44. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position V68. In some embodiments of an IL-2 conjugate described herein, the position of the structure of the formula (XVI) and (XVII) or a mixture of the formula (XVI) and (XVII) in the amino acid sequence of the IL-2 conjugate of SEQ ID NO: 3 is located at position L71. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XVI) to the amount of the structure of formula (XVII) comprising the total amount of the conjugate of IL-2 is approximately 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XVI) to the amount of the structure of formula (XVII) comprising the total amount of the conjugate of IL-2 is higher than 1:1. In some embodiments of an IL-2 conjugate described herein, the ratio of the amount of the structure of formula (XVI) to the amount of the structure of formula (XVII) comprising the total amount of the conjugate of IL-2 is less than 1:1. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from K34, F41, F43, K42, E61 , P64, R37, T40, E67, Y44, V68, and L71, and where n is an integer from 100 to about 1150, or from about 100 to about 1100, or from about 100 to about 1000, or from about 100 to about 900, or about 100 to about 750, or about 100 to about 700, or about 100 to about 600, or about 100 to about 575, or about 100 to about 500, or about 100 to about 450 , or from about 100 to about 350, or from about 100 to about 275, or from about 100 to about 230, or from about 150 to about 475, or from about 150 to about 340, or from about 113 to about 340, or from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 340 to about 795, or from about 341 to about 682, or from about 568 to about 909, or about 227 to about 1500, or about 225 to about 2280, or about 460 to about 2160, or about 460 to about 2050, or about 341 to about 1820, or about 341 to about 1710, or about 341 to about 1250, or from about 225 to about 1250, or from about 341 to about 1250, or from about 341 to about 1136, or from about 341 to about 1023, or from about 341 to about 910, or from about 341 to about 796, or RczRnn / ίζηζ / Ε / γι about 341 to about 682, or about 341 to about 568, or about 114 to about 1000, or about 114 to about 950, or about 114 to about 910, or about 114 to about 800 , or from about 114 to about 690, or from about 114 to about 575. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XVI) and (XVII) is a integer that is selected from 2, 5, 10, 11,22, 23, 113, 114, 227, 228, 340, 341,454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909, 910, 1021, 1022, 1023, 1135, 1136, 1137, 1249, 1250, 1251, 1362, 1363, 1364, 1476, 1477, 1478, 1589, 1590, 1591, 1703, 17 04, 1705, 1817, 1818,1819, 1930, 1931, 1932, 2044, 2045, 2046, 2158, 2159, 2160, 2271,2272, 2273, 2839, 2840, 2841, 2953,2954, 2955,3408, 3409,3410, 3976, 3977, 3978,4544, 4545 and 4546. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, and where n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate As described herein, n in the compounds of formula (XVI) and (XVII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908 , 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where n is a integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of the formula (XVI) and (XVII) is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XVI) and (XVII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is approximately RczRnn / ίζηζ / Ε / γι 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where n is an integer of approximately 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein, n in the compounds of formula (XVI) and (XVII) is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is from about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI ) or (XVII), or a mixture of (XVI) and (XVII), where n is an integer such that the molecular weight of the PEG fraction is in the range of about 1000 Daltons to about 200,000 Daltons, or from about 2000 Daltons to about 150,000 Daltons, or from about 3000 Daltons to about 125,000 Daltons, or from about 4000 Daltons to about 100,000 Daltons, or from about 5000 Daltons to about 100,000 Daltons, or from about 6000 Daltons to about 90,000 Daltons, or from about 7000 Daltons to about 80,000 Daltons, or from about 8000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 70,000 Daltons, or from about 5000 Daltons to about 65,000 Daltons, or from about 5000 Daltons to about 60,000 Daltons, or from about 5000 Daltons to about 50,000 Daltons, or from about 6000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 50,000 Daltons, or from about 7000 Daltons to about 45,000 Daltons, or from about 7000 Daltons to about 40,000 Daltons, or from about 8000 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 40,000 Daltons, or from about 8500 Daltons to about 35,000 Daltons, or from about 9000 Daltons to about 50,000 Daltons, or from about 9000 Daltons to about 45,000 Daltons, or from about 9000 Daltons to about 40,000 Daltons, or from about 9000 Daltons to about 35,000 Daltons, or from about 9000 Daltons to about 30,000 Daltons, or from about 9500 Daltons to about 35,000 Daltons, or from about 9500 Daltons to about 30,000 Daltons, or from approximately 10,000 Daltons to approximately 50,000 Daltons, or from approximately 10,000 Daltons to approximately 45,000 Daltons, or from approximately 10,000 RczRnn / Lznz / E / Yii Daltons to approximately 40,000 Daltons, or from approximately 10,000 Daltons to approximately 35,000 Daltons, or from approximately 10,000 Daltons to approximately 30,000 Daltons, or from approximately 15,000 Daltons to approximately 50,000 Daltons, or from approximately 15,000 Daltons to approximately 45,000 Daltons, or from approximately 15,000 Daltons to approximately 40,000 Daltons, or from approximately 15,000 Daltons to approximately 35,000 Daltons, or from approximately 15,000 Daltons to approximately 30,000 Daltons, or from approximately 20,000 Daltons to approximately 50,000 Daltons, or from approximately 20,000 Daltons to approximately 45,000 Daltons, or from approximately 20,000 Daltons to approximately 40,000 Daltons, or from approximately 20,000 Daltons to approximately 35,000 Daltons, or from approximately 20,000 Daltons to approximately 30,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI ) or (XVII), or a mixture of (XVI) and (XVII), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltons, approx. 90,000 Daltons, approximately 100,000 Daltons , approximately 125,000 Daltons, approximately 150,000 Daltons, approximately 175,000 Daltons, or approximately 200,000 Daltons. Described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI ) or (XVII), or a mixture of (XVI) and (XVII), where n is an integer such that the molecular weight of the PEG fraction is approximately 5000 Daltons, approximately 7500 Daltons, approximately 10,000 Daltons, approximately 15,000 Daltones, approximately 20,000 Daltones, approximately 25,000 Daltones, approximately 30,000 Daltones, approximately 35,000 Daltones, approximately 40,000 Daltones, approximately 45,000 Daltones, or approximately 50,000 Daltones. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from F41, F43, K42, E61, and P64, m is an integer from 0 to 6, and n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 2, and n is an integer selected from 454, 455, 568, 569, 680 , 681,682, 794, 795, 796, 908, RczRnn / ίζηζ / Ε / γι 909, 910, 1021, 1022, 1023, 1135, 1136, 1137 and 1249. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is selected from E61 and P64, and where m is a integer from 0 to 6, and n is an integer from about 450 to about 800, or about 454 to about 796, or about 454 to about 682, or about 568 to about 909. IL-2 described herein in the compounds of the formula (XVI) and (XVII), m is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681,682, 794, 795, 796, 908, 909 and 910. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is E61, and where m is an integer of 0 to 6, and n is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate that described herein in the compounds of the formula (XVI) and (XVII), m is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795, 796, 908, 909 and 910. In some embodiments, n is about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. In some embodiments described herein are IL-2 conjugates comprising the amino acid sequence of SEQ ID NO: 3 in which at least one amino acid residue in the IL-2 conjugate is replaced by the structure of the formula (XVI) or (XVII), or a mixture of (XVI) and (XVII), where the amino acid residue in SEQ ID NO: 3 that is replaced is P64, and where m is an integer of 0 to 6, and π is an integer from about 450 to about 800, or from about 454 to about 796, or from about 454 to about 682, or from about 568 to about 909. In some embodiments of an IL-2 conjugate described herein in the compounds of formula (XVI) and (XVII), m is 2, and n is an integer selected from 454, 455, 568, 569, 680, 681, 682, 794, 795 , 796, 908, 909 and 910. In some embodiments, π is about 500 to about 1000. In some embodiments, n is about 550 to about 800. In some embodiments, n is about 681. Described herein are pharmaceutical compositions comprising an effective amount of an IL conjugate described herein and one or more pharmaceutically acceptable excipients. Described herein are methods of treating cancer in a subject, comprising administering to a subject in need thereof an effective amount of an IL-2 conjugate described RczRnn / Lznz / B / Yi herein. In some embodiments of a method of treating cancer described herein, the cancer in the subject is selected from renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC), squamous cell cancer of the head and neck (HNSCC), classical Hodgkin lymphoma (cHL), primary mediastinal large B-cell lymphoma (PMBCL), urothelial carcinoma, cancer with microsatellite instability, cancer with microsatellite stability, gastric cancer, cervical cancer, hepatocellular carcinoma (HCC), carcinoma Merkel cell carcinoma (MCC), melanoma, small cell lung cancer (SCLC), esophageal cancer, glioblastoma, mesothelioma, breast cancer, triple negative breast cancer, prostate cancer, castration-resistant prostate cancer, prostate cancer metastatic castration-resistant prostate having defects in the DNA damage response (DDR), bladder cancer, ovarian cancer, tumors with moderate to low mutational burden, cutaneous squamous cell carcinoma (CSCC), skin cancer squamous cell (SCSC), tumors that express little or no PD-L1, tumors that have spread systemically to the liver and CNS beyond the anatomical site of primary origin, and diffuse large B-cell lymphoma. Described herein are methods of treating cancer in a subject, comprising administering to a subject in need thereof an effective amount of an IL-2 conjugate described herein. In some embodiments of a method of treating cancer described herein, the cancer in the subject is cholangiocarcinoma. In some embodiments of a method of treating cancer described herein, the cancer in the subject is selected from renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC), urothelial carcinoma and melanoma. In some embodiments of a method of treating cancer described herein, the IL-2 conjugate is administered to the subject in need once every two weeks, once every three weeks, once every 4 weeks, once every 5 weeks, once every 6 weeks, once every 7 weeks or once every 8 weeks. In some embodiments of a method of treating cancer described herein, the IL-2 conjugate is administered to the subject in need thereof once a week or once every two weeks. In some embodiments of a method of treating cancer described herein, the IL-2 conjugate is administered to the subject in need thereof once a week. In some embodiments of a method of treating cancer described herein, the IL-2 conjugate is administered to the subject in need thereof once every two weeks. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause vascular extravasation syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 2, grade 3 or grade 4 vascular extravasation syndrome in the subject. . In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 2 vascular extravasation syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 3 vascular extravasation syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the syndrome. RczRnn / Lznz / E / Yi; of grade 4 vascular extravasation in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause loss of vascular tone in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause extravasation of plasma proteins and fluid into the extravascular space in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause hypotension or reduced organ perfusion in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause an alteration of neutrophil function in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause a reduction in chemotaxis in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject is not associated with an increase in the risk of spread of infection in the subject. In some embodiments of a method of treating cancer described herein, the spread of infection is septicemia or bacterial endocarditis. In some embodiments of a method of treating cancer described herein, the spread of infection is septicemia. In some embodiments of a method of treating cancer described herein, the spread of infection is bacterial endocarditis. In some embodiments of a method of treating cancer described herein, the subject is treated for any bacterial infection prior to administration of the IL-2 conjugate. In some embodiments of a method of treating cancer described herein, the subject is treated with an antibacterial agent selected from oxacillin, nafcillin, ciprofloxacin and vancomycin prior to administration of the IL-2 conjugate. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not exacerbate a preexisting or initial presentation of an autoimmune disease or inflammatory disorder in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not exacerbate a preexisting or initial presentation of an autoimmune disease in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not exacerbate a preexisting or initial presentation of an inflammatory disorder in the subject. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is selected from Crohn's disease, scleroderma, thyroiditis, inflammatory arthritis, diabetes mellitus, oculo-bulbar myasthenia gravis, IgA crescentic glomerulonephritis, cholecystitis, cerebral vasculitis, Stevens-Johnson syndrome, and bullous pemphigoid. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is Crohn's disease. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is scleroderma. In RczRnn / ίζηζ / Ε / γι some modalities of a method of treating the cancer described herein, the autoimmune disease or the inflammatory disorder in the subject is thyroiditis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is inflammatory arthritis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is diabetes mellitus. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is oculobulbar myasthenia gravis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is IgA crescentic glomerulonephritis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is cholecystitis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is cerebral vasculitis. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is Stevens-Johnson syndrome. In some embodiments of a method of treating cancer described herein, the autoimmune disease or inflammatory disorder in the subject is bullous pemphigoid. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause changes in mental status, speech difficulties, cortical blindness, limb ataxia or ataxic gait, hallucinations, agitation, obtundation, or coma in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause seizures in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject is not contraindicated in subjects who have a known seizure disorder. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause capillary leak syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 2, grade 3 or grade 4 capillary leak syndrome in the subject. . In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 2 capillary leak syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 3 capillary leak syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause grade 4 capillary leak syndrome in the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause a decrease in the mean arterial pressure in the subject after administration of the IL-2 conjugate. IL-2 to the subject. In some RczRnn / ίζηζ / Ε / γι embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause hypotension in the subject after administration of the IL-2 conjugate -2 to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the subject to have a systolic blood pressure less than 90 mm Hg or a decrease in 20 mm Hg of baseline systolic pressure after administration of IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause edema in the subject after administration of the IL-2 conjugate to the subject. . In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause failure of kidney or liver function in the subject after administration of the conjugate. of IL-2 to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause eosinophilia in the subject after administration of the IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the eosinophil count in the peripheral blood of the subject to exceed 500 each pL thereafter. of the administration of the IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the eosinophil count in the peripheral blood of the subject to exceed 500 pL to 1500 each pL after administration of the IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the eosinophil count in the peripheral blood of the subject to exceed 1500 each pL at 5000 each pL after administration of the IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause the eosinophil count in the peripheral blood of the subject to exceed 5000 each pL thereafter. of the administration of the IL-2 conjugate to the subject. In some embodiments of a method of treating cancer described herein, administration of the effective amount of the IL-2 conjugate to the subject is not contraindicated in subjects receiving an existing regimen of psychotropic medications. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject is not contraindicated in subjects with an existing regimen of nephrotoxic, myelotoxic, cardiotoxic or hepatotoxic medications. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject is not contraindicated in subjects on an existing regimen of aminoglycosides, cytotoxic chemotherapy, doxorubicin, methotrexate or asparaginase. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject does not RczRnn / ίζηζ / Ε / γι is contraindicated in subjects receiving combination regimens containing antineoplastic agents. In some embodiments of a cancer treatment method described herein, the antineoplastic agent is selected from dacarbazine, cis-platinum, tamoxifen, and interferon-alpha. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject does not cause one or more Grade 4 adverse events in the subject following administration of the conjugate of IL-2 to the subject. In some modalities of a cancer treatment method described herein, one or more Grade 4 adverse events of hypothermia, shock, bradycardia, ventricular premature contractions, myocardial ischemia, syncope, hemorrhage, atrial arrhythmia, phlebitis, heart block are selected. second degree atrioventricular disease, endocarditis, pericardial effusion, peripheral gangrene, thrombosis, coronary artery disorder, stomatitis, nausea and vomiting, liver function tests abnormal, gastrointestinal bleeding, hematemesis, bloody diarrhea, gastrointestinal disorder, intestinal perforation, pancreatitis, anemia, leukopenia, leukocytosis, hypocalcemia, alkaline phosphatase increased, blood urea nitrogen (BUN) increased, hyperuricemia, non-protein nitrogen (NPN) increased, respiratory acidosis, somnolence, agitation, neuropathy, paranoid reaction, convulsion, seizure big bad type; delirium, asthma, pulmonary edema, hyperventilation, hypoxia, hemoptysis, hypoventilation, pneumothorax, mydriasis, pupil disorder, abnormal renal function, renal failure, and acute tubular necrosis. In some embodiments of a cancer treatment method described herein, administration of the effective amount of IL-2 conjugate to a group of subjects does not cause one or more Grade 4 adverse events in more than 1% of cases. the subjects after administration of the IL-2 conjugate to the subjects. In some modalities of a cancer treatment method described herein, one or more Grade 4 adverse events of hypothermia, shock, bradycardia, ventricular premature contractions, myocardial ischemia, syncope, hemorrhage, atrial arrhythmia, phlebitis, heart block are selected. second degree atrioventricular disease, endocarditis, pericardial effusion, peripheral gangrene, thrombosis, coronary artery disorder, stomatitis, nausea and vomiting, liver function tests abnormal, gastrointestinal bleeding, hematemesis, bloody diarrhea, gastrointestinal disorder, intestinal perforation, pancreatitis, anemia, leukopenia, leukocytosis, hypocalcemia, alkaline phosphatase increased, blood urea nitrogen (BUN) increased, hyperuricemia, non-protein nitrogen (NPN) increased, respiratory acidosis, somnolence, agitation, neuropathy, paranoid reaction, convulsion, convulsion big bad type; delirium, asthma, pulmonary edema, hyperventilation, hypoxia, hemoptysis, hypoventilation, pneumothorax, mydriasis, pupil disorder, abnormal renal function, renal failure, and acute tubular necrosis. In some embodiments of a cancer treatment method described herein, administration of the effective amount of IL-2 conjugate to a group of subjects does not cause one or more adverse events in more than 1% of the subjects after of IL-2 conjugate administration to subjects, in which one or more adverse events are selected from duodenal ulceration, intestinal necrosis, myocarditis, supraventricular tachycardia, permanent or transient blindness after optic neuritis, transient ischemic attacks , meningitis, cerebral edema, pericarditis, allergic interstitial nephritis and tracheoesophageal fistula. In some modalities RczRnn / ίζηζ / Ε / γι of a cancer treatment method described herein, administration of the effective amount of IL-2 conjugate to a group of subjects does not cause one or more adverse events in more than 1% of the subjects following administration of the IL-2 conjugate to the subjects, in which one or more adverse events of malignant hyperthermia, cardiac arrest, myocardial infarction, pulmonary emboli, stroke, intestinal perforation, liver failure or kidney, severe depression leading to suicide, pulmonary edema, respiratory arrest, respiratory failure. In some embodiments of a cancer treatment method described herein, administration of the effective amount of IL-2 conjugate to a subject does not result in the production of neutralizing antibodies against the IL-2 conjugate. In some embodiments of a cancer treatment method described herein, administration of the IL-2 conjugate to the subject increases the number of CD8 + T cells and peripheral natural killer (NK) cells in the subject without increasing the number of regulatory peripheral CD4+ T lymphocytes in the subject. In some embodiments of a cancer treatment method described herein, administration of the IL-2 conjugate to the subject increases the number of peripheral CD8+ T cells and NK cells in the subject without increasing the number of peripheral eosinophils in the subject. subject. In some embodiments of a cancer treatment method described herein, administration of the IL-2 conjugate to the subject increases the number of intratumoral CD8+ T cells and NK cells in the subject without increasing the number of intratumoral CD4+ T cells. regulators in the subject. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL2 conjugate to the subject does not require the availability of an acute care facility or qualified cardiopulmonary or intensive care medicine specialists. . In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject does not require the availability of an intensive care facility. In some embodiments of a cancer treatment method described herein, administration of the effective amount of the IL-2 conjugate to the subject does not require the availability of specialists trained in cardiopulmonary or intensive care medicine. Brief description of the figures The novel features of the invention are set forth with particularity in the attached claims. A better understanding of the features and advantages of this invention will be obtained by reference to the following detailed description which sets forth the illustrative embodiments, in which the principles of the invention are used, and the accompanying drawings: Figure 1 shows illustrative unnatural amino acids. This Figure is an adaptation of Figure 2 from Young et al., “Beyond the canonical 20 amino acids: expanding the genetic lexicon,” J. of Biological Chemistry 285(15): 11039-11044 (2010). Figures 2A to 2B show illustrative unnatural amino acids. Figure 2A shows illustrative derivatives of the Plant. Figure 2B shows illustrative phenylalanine derivatives. Figures 3A to Figure 3D show illustrative unnatural amino acids. These amino acids RczRnn / ίζηζ / Ε / γι unnatural (UAA) were genetically encoded in proteins (Figure 3A - UAA N.51 -42; Figure 3B - UAA N.s43-89; Figure 3C - UAA N.s90-128; Figure 3D- UAA N.e129-167). Figures 3A to 3D are adopted from Table 1 of Dumas etal., Chemical Science 2015, 6, 50-69. Figures 4A to Figure 4C show the surface plasmon resonance (SPR) analysis of the native IL-2 conjugates, P65_30kD, P65_5kD, E62_30kD, E62_5kD, and F42_30kD PEG. Figure 4A shows SPR analysis of IL-2 variants bound to immobilized IL-2 Ra. Figure 4A shows SPR analysis of IL-2 variants bound to immobilized IL-2 Rp. Figure 4C shows the SPR analysis of the recombinant IL-2 variants and the F42_30kD variant of IL-2 bound to the immobilized IL-2 Ray to the IL-2 Rp. Figures 5A to Figure 5F show exemplary dose response curves of the IL2 variant for pSTAT5 signaling in primary human LRS cell populations. Figure 5A: native IL-2; Figure 5B: P65_30kD; Figure 5C: K64_30kD; Figure 5D: K43_30kD; Figure 5E: K35_30kD, and Figure 5F: F42_30kD. Figures 6A to 6C show that PEG and residue substitution contribute to the non-alpha pharmacology of IL-2 variants. Figure 6A: native IL-2; Figure 6B: E62K; Figure 6C: E62_30kD. Figure 7 shows that the non-alpha pharmacology of IL-2 variants is independent of PEG size. Figure 8 shows the mean (±SD) plasma concentration versus time profiles following a single intravenous bolus dose of aldesleukin (IL-2), E62_5, E62_30, and P65_30 to C57BL / 6 mice. Figure 9 shows the percentage of pSTAT5+ CD8+ T cells compared to temporal cells in the peripheral blood following treatment with a single intravenous bolus dose of P65_30 or aldesleukin to C57BL / 6 mice. Figures 10A to Figure 10C show the percentage of CD8+ T cells (Figure 10A), NK cells (Figure 10B), and CD4+ Treg cells (Figure 10C) in the PBMC population following treatment with a single intravenous bolus dose of P65_30 or aldesleukin (IL-2). Blood was drawn by cardiac puncture at the indicated time points and immune cell populations were assessed by flow cytometry. Each data point represents an average of 3 replicates at each time point, ±SEM. Figures 11A to Figure 11B show the differences between P65_30 and IL-2 (aldesleukin) in stimulation of CD8+CD44+ memory T cell proliferation within the CD3+ population following treatment with a single intravenous bolus dose of P65_30 or aldesleukin (IL-2). Blood was drawn by cardiac puncture at the indicated time points and immune cell populations were assessed by flow cytometry. Data were analyzed using unpaired Student's t test. *** designates P values ​​<0.001. Figure 11A shows the proliferation of CD8+CD44+ memory T cells at 72, 96 and 120 hours. Figure 11B shows flow cytometry analysis of those cells at the 120 hour time point. Figures 12A to Figure 12B show the increase in tumor infiltrating lymphocytes (TIL) RczRnn / ίζηζ / Ε / γι versus time in C57BI6 mice bearing benign B16F10 tumors after treatment with a single intravenous bolus dose of P65_30. Figure 12A shows the percentage of NK, CD8+ T, and CD4+ T reg cells in animals treated with P65_30 compared to untreated (vehicle) on Day 5 of treatment. Figure 12B shows the ratio of CD8+ / CD4+ Treg cells in treated and control (vehicle) P65_30 animals. Data were analyzed using unpaired Student's t test. *** designates P values ​​<0.001. Figures 13A to Figure 13B show the plasma levels of mouse IL-2, TNF-α, IFNy, IL5 and IL-6 after treatment with a single intravenous bolus dose of P65_30 or aldesleukin (IL-2) at increasing levels (0.01 - 5 mg / kg). The concentration of each cytokine in plasma was determined by the ELISA test (Abcam, Cambridge, United Kingdom). For each dose group N=3 mice, samples were collected at 4, 34, and 72 hours post-dose. Figure 13A shows cytokine levels for animals dosed with aldesleukin and Figure 13B for animals dosed with P65_30. Figure 14 shows white blood cell, lymphocyte, and eosinophil counts (mean ± SD) following a single intravenous dose of P65_30kD to male Cynomolgus monkeys. Figures 15A to Figure 15B show dose response curves of an exemplary IL-2 variant for pSTAT5 signaling in the human LRS primary cell (Figure 15A) and proliferation response in CTLL-2 populations of mice. (Figure 15B). Figures 16A to Figure 16B show that PEG IL-2 compounds can specifically expand immune cell populations ex vivo in primary lymphocytes, compared to a normal IL-2 control. Figure 16A shows the expansion of immune cells after treatment with IL-2 (control). Figure 16B shows the expansion of immune cells after treatment with P65_30kD. Figures 17A to Figure 17B show sensorgrams of binding responses for rhlL-2 (recombinant human interleukin-2, Figure 17A) and the synthetic conjugate IL-2_P65[AzK_L1_PEG30kD]1 (Figure 17B) on the alpha surfaces of IL-2R . No significant binding response was detected for IL-2 P65[AzK L1 PEG30kD]-1 under these conditions. Figures 17C to Figure 17D show the sensorgrams of samples of rhlL-2 (recombinant human interleukin-2, Figure 17C) and of the synthetic conjugate IL-2_P65[AzK_L1_PEG30kD]-1 (Figure 17D) binding to the beta surfaces of IL-2R. Figure 18 shows a gating strategy for cell sorting of Tregs using flow cytometry. Cells were first synchronized in singlets using FSC-A by FSC-H to exclude any aggregates or doublets (Singlet Gate, 1st panel). Within this gate, cells were gated in a medium to high forward scatter (FSC-A) and side scatter (SSC-A) to exclude red blood cells, debris, and granulocytes (Lymphocyte gate, 2.d0panel ). T cells were then synchronized as the 3rd CD3+, CD56 / 16 negative population panel. NK cells were identified as CD3 negative, CD56 / 16 high population, 3rdpanel. T cells were divided into CD4+ T cells and CD8+ T cells (4th panel). Tregs were then separated from CD4+ T cells as the population RczRnn / Lznz / E / Yi CD25h¡ x C127lo, 5th panel. Figure 19 shows the stability of the compound IL-2_P65[AzK_L1_PEG30kD]-1 in human serum at three concentrations up to 168 hours, as described in Example 15. Detailed description of the invention Cytokines comprise a family of cell signaling proteins such as chemokines, interferons, interleukins, lymphokines, tumor necrosis factors, and other growth factors that play a role in the innate and adaptive homeostasis of immune cells. Cytokines are produced by immune cells such as macrophages, B lymphocytes, T lymphocytes, and mast cells, endothelial cells, fibroblasts, and various stromal cells. In some cases, cytokines modulate the balance between humoral and cellular immune responses. Interleukins are signaling proteins that modulate the development and differentiation of T and B lymphocytes, cells of the monocyte lineage, neutrophils, basophils, eosinophils, megakaryocytes, and hematopoietic cells. Interleukins are produced by CD4 helper T and B lymphocytes, monocytes, macrophages, endothelial cells, and other tissue residents. Interleukin 2 (IL-2) is a type 1 pleiotropic cytokine whose structure comprises a bundle of four 15.5 kDa α-helixes. The precursor form of IL-2 is 153 amino acid residues in length, with the first 20 amino acids forming a signal peptide and residues 21-153 forming the mature form. IL-2 is produced primarily by CD4+ T cells after antigen stimulation and, to a lesser extent, by CD8+ cells, natural killer and T cells, activated dendritic cells (DCs), and mast cells. . IL-2 signaling occurs through interaction with specific combinations of IL-2 receptor subunits (IL-2R), IL2Ra (also known as CD25), IL-2Rp (also known as CD122), and IL-2. 2Ry (also known as CD132). The interaction of IL-2 with IL-2Ra forms the IL2 low affinity receptor complex with a Kd of around 10 -8M. The interaction of IL-2 with IL-2Rp and IL-2Ry forms the IL-2 intermediate affinity receptor complex with a Kd of about 109M. The interaction of IL-2 with the three subunits, IL-2Ra, IL-2Rp, and IL-2Ry, forms the high-affinity IL-2 receptor complex with a Kd of around >10-11M. In some cases, IL-2 signaling through the high-affinity IL-2Rapy complex modulates the activation and proliferation of regulatory T cells. Regulatory T cells, or CD4+CD25+Foxp3+ regulatory T (Treg) cells, mediate the maintenance of immune homeostasis by suppressing effector cells such as CD4+ T cells, CD8+ T cells, B cells, In some cases, Treg cells are generated from the thymus (tTreg cells) or induced from naïve T cells in the periphery (pTreg cells). In some cases, Treg cells are considered as the mediator of peripheral tolerance. Indeed, in one study, transfer of CD25-depleted peripheral CD4+T cells produced a variety of autoimmune diseases in nude mice, while cotransfer of CD4+CD25+T cells suppressed the development of autoimmunity {[Sakaguchi, et al ., RczRnn / ίζηζ / Ε / γι “Immunologicself-tolerance maintained by activated T cells expressing IL-2 receptor alpha-chains (CD25),” J. Immunol. 155(3): 1151-1164 (1995)]}. Increasing the Treg population decreases effector T cell proliferation and suppresses T cell autoimmunity and antitumor responses. IL-2 signaling through the intermediate affinity IL-2Rpy complex modulates the activation and proliferation of CD8+ effector T cells (Teff), NK cells, and NKT cells. Teff CD8+ cells (also known as cytotoxic T cells, Te cells, cytotoxic T cells, CTL, cytolytic T cell, cytolytic T cells, Tcon or cytolytic T cells) are T cells that recognize and kill damaged cells, cancer cells and cells infected by pathogens. NK and NKT cells are types of lymphocytes that, similar to CD8+ Teff cells, target cancer cells and pathogen-infected cells. In some cases, IL-2 signaling is used to modulate T cell responses and subsequently for the treatment of cancer. For example, IL-2 is administered in a high-dose form to induce the expansion of Teff lymphocyte populations for the treatment of cancer. However, high dose of IL2 leads to concomitant stimulation of Treg cells that dampen antitumor immune responses. High doses of IL-2 also induce toxic adverse events mediated by the commitment of cells expressing the IL-2R alpha chain in the vasculature, including innate immune cells type 2 (ILC-2), eosinophils, and endothelial cells. This leads to eosinophilia, capillary leak, and vascular leak syndrome (VLS). Adoptive cell therapy allows doctors to effectively harness a patient's own immune cells to fight diseases such as proliferative diseases (e.g., cancer) and infectious diseases. In a non-limiting example, T cells can be harvested from the patient, reengineered to attack a specific antigen on the surface of malignant cells, and reintroduced into the patient's body to specifically attack malignant cells. Additionally, adoptive cell therapies provide a sustained response in the body by signaling immune cells to grow and divide long after the re-engineered cells are reintroduced into the patient's immune system. In certain embodiments, disclosed herein is a method of selectively regulating distinct populations of lymphocytes (e.g., CD4+ helper cells, CD8+ naïve and memory effector cells, NK cells, or NKT cells) through cytokine / cytokine receptor signaling. In some cases, the cytokine comprises an interleukin, an interferon, or a tumor necrosis factor. In some cases, the cytokine is a cytokine conjugate, for example, an interleukin conjugate, an interferon conjugate, or a tumor necrosis factor conjugate. Additional embodiments described herein comprise pharmaceutical compositions and kits comprising one or more cytokine conjugates described herein. In some embodiments, also described herein is a method of selectively regulating the populations of CD4+ helper cells, CD8+ naïve and memory effector cells, NK cells and / or NKT cells through IL-2 / IL-2R signaling. . In some cases, IL-2 is a RczRnn / ίζηζ / Ε / γι conjugate of IL-2, which interacts with the intermediate affinity IL-2Rpy complex, optionally with a potency similar to that of the IL-2Rapy complex, and with a weakened interaction of IL-2Ra relative to Wild type IL2. In some embodiments, methods of treating a cancer with the use of an IL-2 conjugate described herein are described below. In additional embodiments, pharmaceutical compositions and kits comprising one or more IL-2 conjugates described herein are described herein. In some embodiments, IL-2 conjugates comprise conjugated moieties (e.g., a PEG) that contribute to an increase or decrease in the clearance rate, or plasma half-life in a subject, without affecting pharmacokinetics, including the desired interactions between cytokines and receptors and the expansion of immune cells. In some embodiments, presented herein are reagents that can be used to develop adoptive cellular therapies comprising cells engineered to express modified cytokines that result in selective cytokine-receptor interactions and expansion of immune cells. In some embodiments, the reagents comprise a nucleic acid construct encoding the IL-2 conjugates described above. Also disclosed are adoptive cell therapies comprising the IL-2 conjugates described above and which may be useful for the treatment of the proliferative or infectious diseases described herein. In some embodiments, compositions that generate selective cytokine-receptor interactions and immune cell expansion are disclosed herein. In some embodiments, the reagents comprise a nucleic acid construct encoding the IL-2 conjugates described above. Also disclosed are pharmaceutical compositions comprising the IL-2 conjugates described above and which may be useful for the treatment of the proliferative or infectious diseases described herein. Cytokine conjugates In some embodiments, described herein are cytokine conjugates. In some cases, the cytokine comprises an interleukin, a tumor necrosis factor, an interferon, a chemokine, a lymphokine, or a growth factor. In some cases, the cytokine is an interleukin. In some cases, the cytokine is an interferon. In other cases, the cytokine is a tumor necrosis factor. In other cases, the cytokine is a growth factor. In some embodiments described herein it is an interleukin conjugate. Exemplary interleukins include, but are not limited to, interleukin 2 (IL-2). IL-2 conjugates Described herein are the polypeptides shown in Table 20. In some embodiments, the IL-2 conjugates described herein are specified in Table 20. RczRnn / ίζηζ / Ε / γι Table 20 Name Sequence SEQ ID NO: IL-2 (homo sapiens) (mature form) APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTF MCEYADETATIVEFLNRWITFCQSIISTLT 1 IL-2 (homo sapiens) (precursor) Ν.θ NCBI accession: AAB46883.1 MYRMQLLSCIALSLALVTNSAPTSSSTKKTQLQLEHLLLDLQMILNGINNY KNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLR PRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 2 aldesleukin PTSSSTKKTQLQLEHLLLDLQMILNG INNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 3 IL-2P65X APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMP KKAT ELKHLQCLEEELKXLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTF MCEYADETATIVEFLNRWITFSQSIISTLT 5 IL-2_E62X APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEXLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTF MCEYADE TATIVEFLNRWITFSQSIISTLT 6 IL-2F42X APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTXKFYMPKKAT ELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTF MCEYADETATIVEFLNRWITFSQSIISTLT 7 IL-2K43X APTSSSTKKTQLQLEHLLLDLQMILNGIN NYKNPKLTRMLTFXFYMPKKAT ELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTF MCEYADETATIVEFLNRWITFSQSIISTLT 8 IL-2K35X APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPXLTRMLTFKFYMPKKAT ELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLE LKGSETTF MCEYADETATIVEFLNRWITFSQSIISTLT 9 IL-2_P65[AzK] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELK [AzK]LEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSE TTFMCEYADETATIVEFLN RWITFSQSIISTLT 10 IL-2_E62[AzK] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEE[AzKlLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELK 1 2 IL-2_K43[AzK] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTF[AzKlFYMPK KATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSE TTFMCEYADETATIVEFLN RWITFSQSI ISTLT 13 IL-2_K35[AzK] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNP[AzKlLTRMLTFKFYMPK KATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSE TTFMCEYADETATIVEFLN RWITFSQSI ISTLT 14 IL-2_P65[AzK_PEG] APTSSST KKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELKfAzK PEG1LEEVLNLAQSKNFHLRPRDLISNINVIVLEL KGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 15 IL-2_E62[AzK_PEG] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFK YMPKKATELKHLQCLEEELKPLEEV LNLAQSKNFHLRPRDLISNINVIVLEL KGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 17 IL- 2_K43[AzK_PEG] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFrAzK PEG1F YMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLEL KGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 18 RCZRnn / ί7Π7 / Ε / ΥΙ IL-2_K35[AzK_PEG] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK PEG1LTRMLTFKF YMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLEL KGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 19 IL-2_P65[AzK_PEG5kD] APTSSST KKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELKÍAzK PEG5kD1LEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 20 IL-2_E62[AzK_PEG5kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNP KLTRMLTFKFYMPKKAT ELKHLQCLEEÍAzK PEG5kD1LKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 21 IL-2_F42[AzK_PEG5kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK PEG5kD 1KFY MPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 22 IL-2_K43[AzK_PEG5kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK PEG5k DIFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 23 IL-2_K35[AzK_PEG5kD] APTSSSTKKTQLQLEHLLLDLQMILNGIN NYKNPrAzK PEG5kD1LTRMLT FKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 24 IL- 2_P65[AzK_PEG30kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT EL PEG30k D1LKPLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 26 IL- 2_F42[AzK_PEG30kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK PEG30k D1KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRP RDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 27 IL - 2_K43[AzK_PEG30kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK PEG30 kDIFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 28 IL- 2_K35[AzK_PEG3 0kD] APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK PEG30kD]LTRML TFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 29 IL-2_P65X-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYK NPKLTRMLTFKFYMPKKATE LKHLQCLEEELKXLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 30 IL-2E62X-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEXLKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 31 IL-2F42X-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTXKFYMPKKATE LKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 32 IL-2K43X-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFXFYMPKKATE LKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 33 YMPKKATE LKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFM CEYADETATIVEFLNRWITFSQSIISTLT 34 IL-2_P65[AzK]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEELKJAzKlLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSET TFMCEYADETATIVEFLNRWITFSQSIISTLT 35 IL-2_E62[AzK]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEE[AzKlLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSET TFMCEYADETATIVEFLNRWITFSQSIISTLT 36 IL -2_F42[AzK] -1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLT[AzKlKFYMPKK ATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSET TFMCEYADETATIVEFLNRWITFSQSIISTLT 37 IL-2_K43[AzK]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRML TF[AzKlFYMPKK ATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSET TFMCEYADETATIVEFLNRWITFSQSIISTLT 38 IL-2_K35[AzK]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNP[AzKlLTRMLTFKFYMPKK ATELKHLQCLEEELKPLEEVLNLAQSK NFHLRPRDLISNINVIVLELKGSET TFMCEYADETATIVEFLNRWITFSQSIISTLT 39 RczRnn / Lznz / Ε / γΐΛΐ IL- 2_P65[AzK_L1_PEG]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEELKÍAzK L1 PEG1LEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 40 IL-2_E62[AzK_ L1_ PEG-1 QMILNGINNYKNPKLTRMLTÍAzK L1 PEG1 KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 42 IL-2_K43[AzK_ L1_PEG ] -1 ILNGINNYKNPÍAzK L1 PEG1LTRMLTFK FYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLE LKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 44 IL-2_P65[AzK_ L1 PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKK ATE LKHLQCLEEELKÍazK L1 PEG5kD]LEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 45 IL-2_E62[AzK_ L1_PEG5kD]- 1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEÍAzK L1 PEG5kD]LKPLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 46 IL-2_F42[AzK_ L1_PEG5kD]-1 PTSSSTKKTQLQ LEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK L1 PEG5 kDlKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINV IVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 47 IL-2_K43[AzK_ L1_PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYK NPKLTRMLTFÍAzK L1 PEG 5kDlFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINV IVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 48 IL-2_K35[AzK_ L1_PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK L1 PEG5kD1LTRML TFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVI VLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 49 IL-2_P65[AzK_ L1_PEG30kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHL QCLEEELKÍAzK L1 PEG30kD1LEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 50 IL-2_E62[AzK_ L1_PEG30kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEÍAzK L1 P EG30kD1LKPLEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 51 IL-2_F42[AzK_ L1_PEG30kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK L1 PEG3 OkDlKFYMPKKATELKHLQCLEEELKPLEEV LNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 52 IL -2_K43[AzK_ L1_PEG30kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK L1 PEG 30kDJFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 53 IL-2_K35[A zK_ L1_PEG30kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK L1 PEG30kD1LTRM LTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 54 IL- 2_P65[AzK_L1_PEG ]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELKÍAzK L1 PEG1LEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 55 IL-2_E62[AzK_ L1_PEG] 56 QMILNGINNYKNPKLTRMLTÍAzK L1 PEG 1KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 57 IL-2_K43[AzK_ L1_PEG]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK L1 PE G1FYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 58 IL-2_K35[AzK_ L1_PEG]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK L1 PEG1LTRMLTF 59 EG5kD1LEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 60 RczRnn / Lznz / Ε / γΐΛΐ IL-2_F42 zK_ L1_PEG5kD]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK L1 PEG 5kDlKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 62 IL-2_K43[AzK_ L1_PEG5 kD]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK L1 PE G5kDlFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNIN VIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 63 IL-2_K35[AzK_ L1_PEG5kD]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK L1 PEG5kD1LTR MLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 64 IL-2_P65[AzK_ L1_PEG30 kD]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEELKÍAzK L1 PEG30kD1LEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 65 IL-2_E62[AzK_ L1 PEG30kD]-2 APTSS STKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKAT ELKHLQCLEEÍAzK L1 PEG30kDlLKPLEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 66 IL-2_F42[AzK_ L1_PEG30kD]-2 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK L1 PEG 30kD]KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 67 IL-2_K43[AzK_ L1_PEG30kD]-2 APTSSSTKK TQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK L1 PE G30kD1FYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 68 IL-2_K35[AzK_ L1_PEG30kD]-2 APTSSTKKTQLQLEHLLLDL QMILNGINNYKNPÍAzK L1 PEG30kD1LTR MLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNI NVIVLELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 69 IL-2_P65[AzK_PEG]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKF YMPKKATE LKHLQCLEEELKÍAzK PEG1LEEVLNLAQSKNFHLRPRDLISNINVIVLELK GSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 70 IL-2_E62[AzK_ PEG]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEÍAzK PEG1LKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELK GSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 71 IL-2_F42[AzK_ PEG]-1 PT SSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK PEG1KFY MPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELK GSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 72 IL-2_K43[AzK_ PEG]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRML TFÍAzK PEG1FY MPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELK GSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 73 IL-2_K35[AzK_ PEG] -1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPÍAzK PEG1LTRMLTFKFY MPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELK GSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 74 IL-2_P65[AzK_ PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNG INNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEELKÍAzK PEG5kD1LEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 75 IL- 2_E62[AzK_PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE L KHLQCLEEÍAzK PEG5kD1LKPLEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 76 IL- 2_F42[AzK_PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTÍAzK PEG5kD1 KFYMPKKATELKHLQCLEEEL KPLEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLN RWITFSQSIISTLT 77 IL- 2_K43[AzK_PEG5kD]-1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFÍAzK PEG5kD 1FYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLN RWITFSQSI ISTLT 78 IL- 2_K35[AzK_PE G5kD] -1 LEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEELKÍAzK PEG30kDlLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLN RWITFSQSI ISTLT 80 RczRnn / Lznz / Ε / γΐΛΐ IL2_E62[AzK_PEG30kD]1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATE LKHLQCLEEfAzK PEG30kD1LKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 81 IL2_F42[AzK_PEG3 0kD]1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTIAzK PEG30kD 1KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 82 IL2_K43[AzK_PEG30kD]1 PTSSSTKKTQLQLEHL LLDLQMILNGINNYKNPKLTRMLTFfAzK PEG30k DIFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIV LELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 83 IL2_K35[AzK_PEG30kD]1 PTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPfAzK PEG3 0kD1LTRMLTF KFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVL ELKGSETTFMCEYADETATIVEFLNRWITFSQSIISTLT 84 RczRnn / ίζηζ / Ε / γι X = site comprising a non-natural amino acid. [AzK] = N6-((2-azjdoethoxy¡)-carbon¡l)-L-l¡sina (whose structure is disclosed as compound 90 in FIGURE 30). The compound has CAS registration number 1167421-25-1. [AzK_PEG] = N6-((2-az¡doethoxy)-carbon¡l)-L-l¡sina, stably conjugated to PEG via DBCO-mediated click chemistry, to form a compound comprising a structure of Formula (II) or Formula (III). For example, if specified, PEG5kD indicates a linear polyethylene glycol chain with an average molecular weight of 5 kiloDaltons, capped with a methoxy group. The ratio of regioisomers generated by the click reaction is approximately 1:1 or greater than 1:1. The term DBCO means a chemical moiety comprising a group of dibenzocyclocytes, such as the compound mPEGDBCO illustrated in Scheme 1 of Example 2. The structure of mPEG-DBCO in Scheme 1 of Example 2 illustrates an exemplary structure of a group PEG methoxy. [AzK_L1_PEG] = N6-((2-azidoethoxy)-carbon¡l)-L-l¡sina, stably conjugated to PEG via DBCO-mediated click chemistry, to form a compound comprising a structure of Formula ( IV) or Formula (V). For example, if specified, PEG5kD indicates a linear chain of polyethylene glycol with an average molecular weight of 5 kiloDaltons, capped with a methoxy group. The ratio of regioisomers generated by the click reaction is approximately 1:1 or greater than 1:1. The term DBCO means a chemical moiety comprising a group of dibenzocyclocytes, such as the mPEG-DBCO compound illustrated in Scheme 1 of Example 2. In some embodiments, IL-2 conjugates modified at an amino acid position are described herein. In some cases, the modification is to a naturally occurring amino acid. In some cases, the modification is to a non-natural amino acid. In some cases, an isolated and modified IL-2 polypeptide comprising at least one non-natural amino acid is described herein. In some cases, the IL-2 polypeptide is an isolated and purified mammalian IL-2, for example, a rodent IL-2 protein, or a human IL-2 protein. In some cases, the IL-2 polypeptide is a human IL-2 protein. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1. In In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 1. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 1. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 2. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 2. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 2. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90% , 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 3. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 3. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 3. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98 %, or 99% sequence identity to SEQ ID NO: 4. In further instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 4. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 4. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 5. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 5. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 5. In In additional instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 6. In additional instances, The IL-2 polypeptide comprises the sequence of SEQ ID NO: 6. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 6. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 7. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 7. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 7. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95% , 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 8. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 8. In additional instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 8. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 9. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 9. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 9. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 10. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 10. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 10. In some cases, The IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 11. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 11. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 11. In some cases, the IL-2 polypeptide comprises about 80 %, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 12. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 12. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 12.In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 13. In In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 13. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 13. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to the. RczRnn / Lznz / E / Yi SEQ ID NO: 14. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 14. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 14. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 14. , the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 15. In some cases, The IL-2 polypeptide comprises the sequence of SEQ ID NO: 15. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 15. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 16. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 16. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 16. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95 %, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 17. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 17. In some cases, The IL-2 polypeptide consists of the sequence of SEQ ID NO: 17. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98% , or 99% sequence identity to SEQ ID NO: 18. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 18. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 18. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to the SEQ ID NO: 19. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 19. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 19. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 19. , the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 20. In some cases, The IL-2 polypeptide comprises the sequence of SEQ ID NO: 20. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 20. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 21. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 21. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 21. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95 %, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 22. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 22. In some cases, The IL-2 polypeptide consists of the sequence of SEQ ID NO: 22. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98% , or 99% sequence identity to SEQ ID NO: 23. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 23. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 23. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to the SEQ ID NO: 24. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 24. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 24. In additional cases , the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 25. In additional instances, the IL2 polypeptide comprises the sequence of SEQ ID NO: 25. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 25. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 26. In some cases, RczRnn / ίζηζ / Ε / γι the IL-2 polypeptide comprises the sequence of SEQ ID NO: 26. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 26. In additional cases, the polypeptide IL-2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 27. In additional instances, the IL-2 polypeptide 2 comprises the sequence of SEQ ID NO: 27. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 27. In some cases, the IL-2 polypeptide comprises about 80%, 85 %, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 28. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 28. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 28. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 29. In further instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 29. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 29. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of sequence identity to SEQ ID NO: 30. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 30. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 30. 30. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 31 In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 31. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 31. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 31. 2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 32. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 32. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 32. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 33. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 33. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 33. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97% , 98%, or 99% sequence identity to SEQ ID NO: 34. In further instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 34. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 34. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity. sequence to SEQ ID NO: 35. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 35. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 35. In additional instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 36. In additional cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 36. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 36. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 37. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 37. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 37. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity RczRnn / Lznz / E / Yi; sequence to SEQ ID NO: 38. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 38. In additional instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 38. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 39. In In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 39. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 39. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 40. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 40. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 40. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90 %, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 41. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 41. In In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 41. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97% , 98%, or 99% sequence identity to SEQ ID NO: 42. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 42. In some instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 42. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity of sequence to SEQ ID NO: 43. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 43. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 43. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 44. In In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 44. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 44. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 45. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 45. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 45. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90 %, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 46. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 46. In In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 46. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97% , 98%, or 99% sequence identity to SEQ ID NO: 47. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 47. In some instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 47. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity of sequence to SEQ ID NO: 48. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 48. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 48. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 49. In In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 49. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 49. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to the RczRnn / ίζηζ / Ε / γι 100 SEQ ID NO: 50. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 50. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 50. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 50. , the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 51. In some cases, The IL-2 polypeptide comprises the sequence of SEQ ID NO: 51. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 51. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 52. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 52. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 52. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95 %, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 53. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 53. In some cases, The IL-2 polypeptide consists of the sequence of SEQ ID NO: 53. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98% , or 99% sequence identity to SEQ ID NO: 54. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 54. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 54. In additional instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 55. In further instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 55. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 55. In some instances, The IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 56. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 56. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 56. In additional cases, the IL-2 polypeptide comprises about 80% , 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 57. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 57. In additional cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 57. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 58. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 58. In some cases, the polypeptide IL-2 consists of the sequence of SEQ ID NO: 58. In additional instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99 % sequence identity to SEQ ID NO: 59. In additional instances, the IL2 polypeptide comprises the sequence of SEQ ID NO: 59. In additional instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 59. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 60 In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 60. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 60. In some cases, the IL-2 polypeptide 2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 61. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 61. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 61. In additional cases, the IL-2 polypeptide comprises about 80%, 85%, 90 %, 95%, 96%, 97%, 98%, or 99% sequence identity to the RczRnn / ίζηζ / Ε / γι 101 SEQ ID NO: 62. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 62. In additional instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 62. In some instances , the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 63. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 63. In some instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 63. In additional instances, the IL-2 polypeptide comprises about 80 %, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 64. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 64. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 64. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95% , 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 65. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 65. In some instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 65. In further instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 66. In additional instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 66. In additional instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 66. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 67. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 67. In some instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 67. In additional instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 68. In additional instances, the IL-2 polypeptide -2 comprises the sequence of SEQ ID NO: 68. In further instances, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 68. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 69. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: : 69. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 69. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96 %, 97%, 98%, or 99% sequence identity to SEQ ID NO: 70. In some instances, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 70. In some instances, the IL-2 polypeptide -2 consists of the sequence of SEQ ID NO: 70. In some instances, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99 % sequence identity to SEQ ID NO: 71. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 71. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 71. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO : 72. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 72. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 72. In some cases, the polypeptide of IL-2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 73. In some cases, the IL polypeptide -2 comprises the sequence of SEQ ID NO: 73. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 73. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity RczRnn / ίζηζ / Ε / γι 102 sequence to SEQ ID NO: 74. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 74. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 74. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 75 In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 75. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 75. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 75. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 75. -2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 76. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 76. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 76. In some cases, the IL-2 polypeptide comprises about 80%, 85% , 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 77. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 77 In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 77. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 78. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 78. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 78. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of sequence identity to SEQ ID NO: 79. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 79. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 79. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 80 In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 80. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 80. In some cases, the IL polypeptide -2 comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 81. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 81. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 81. In some cases, the IL-2 polypeptide comprises about 80%, 85% , 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 82. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 82 In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 82. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 83. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 83. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 83. In some cases, the IL-2 polypeptide comprises about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity sequence to SEQ ID NO: 84. In some cases, the IL-2 polypeptide comprises the sequence of SEQ ID NO: 84. In some cases, the IL-2 polypeptide consists of the sequence of SEQ ID NO: 84. . In some cases, the IL-2 polypeptide is a truncated variant. In some cases, the truncation is an N-terminal deletion. In other cases, the truncation is a C-terminal deletion. In other cases, the truncation comprises both the N-terminal and C-terminal deletion. For example, the truncation can be a deletion of at least or about 1,2,3, 4, 5, 6, 7, 8, 9, 10, 11, RczRnn / Lznz / E / Yi 103 12, 13, 14, 15, 20, or more residues from the N-terminus or the C-terminus, or both. In some cases, the IL-2 polypeptide comprises an N-terminal deletion of at least or about 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 , 15, 20, or more residues. In some cases, the IL-2 polypeptide comprises a deletion of RczRnn / ίζηζ / Ε / γι N-terminus of at least or about 1,2, 3, 4, 5, 6, 7, 8, 9, or 10 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 2 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 3 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 4 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 5 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 6 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 7 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 8 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 9 residues. In some cases, and IL-2 comprises an N-terminal deletion of at least or about 10 residues. polypeptide polypeptide polypeptide polypeptide polypeptide polypeptide polypeptide polypeptide polypeptide In some embodiments, the IL-2 polypeptide is a functionally active fragment. In some cases, the functionally active fragment comprises the IL-2 region 10-133, 20-133, 30-133, 10-130, 20-130, 30-130, 10-125, 20-125, 30-125 , 1 -130, or 1 -125, wherein the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region 10-133, in in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region 20-133, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region 30-133, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some In some cases, the functionally active fragment comprises the IL-2 10-125 region, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region. 2 20-125, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region 1 -130, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some cases, the functionally active fragment comprises the IL-2 region 1-125, in which the positions of the residues are in reference to the positions in SEQ ID NO: 1. In some embodiments, described herein is an IL-2 conjugate comprising an isolated, purified and modified IL-2 polypeptide and a conjugated moiety. In some cases, the IL-2 conjugate has a decreased affinity for a subunit of the IL-2 receptor α (IL-2Ra) relative to a wild-type IL-2 polypeptide. In some cases, the conjugated moiety is linked to an amino acid residue that interacts with IL-2Ra (e.g., at the IL-2 / IL-2Ra interface). In some cases, the conjugated moiety binds to an amino acid residue that is close to the IL-2 / IL-2Ra interface (e.g., about 5Á, about 10Á, about 15Á, or about 20Á away from the IL-2 / IL-2Ra interface). As used herein, residues involved in the IL-2 / IL-2Ra interface comprise IL-2 residues that form hydrophobic interactions, hydrogen bonds, or ionic interactions with residues of 104 the IL-2Ra subunit. In some cases, the conjugated moiety is attached to an amino acid residue selected from an amino acid position Y31, K32, N33, P34, K35, T37, R38, T41, F42, K43, F44, Y45, P47, K48, Q57, E60, E61, E62, L63, K64, P65, E68, V69, N71, L72, Q74, S75, K76, N77, M104, C105, E106, Y107, A108, D109, E110, T111, or A112, in which the numbering of the amino acid residues corresponds to SEQ ID NO: 1. In some cases, the position of the amino acids is selected from Y31, K32, N33, P34, K35, T37, R38, T41, F42, K43, F44, Y45, P47, K48, E61, E62, E68, K64, P65, V69, L72, Q74, S75, K76, N77, M104, C105, E106, Y107, A108, D109, E110, T111 and A112. In some cases, the position of the amino acids is selected from N33, P34, K35, T37, R38, M39, T41, F42, K43, F44, Y45, Q57, E60, E61, E62, L63, K64, P65, E68, V69, N71, L72, M104, C105, E106, Y107, A108, D109, E110, T111 and A112. In some cases, the amino acid position is selected from K35, T37, R38, T41, F42, K43, F44, Y45, E61, E62, E68, K64, P65, V69, L72 and Y107. In some cases, the amino acid position is selected from T37, R38, T41, F42, F44, Y45, E61, E62, E68, K64, P65, V69, L72, and Y107. In some cases, the position of the amino acids is selected from T37, R38, T41, F42, F44, Y45, E61, E62, E68, P65, V69, L72, and Y107. In some cases, the position of the amino acids is selected from T37, T41, F42, F44, Y45, P65, V69, L72 and Y107. In some cases, the position of the amino acids is selected from R38 and K64. In some cases, the position of the amino acids is selected from E61, E62 and E68. In some cases, the position of the amino acids is at K35. In some cases, the position of the amino acids is at T37. In some cases, the position of the amino acids is at R38. In some cases, the position of the amino acids is at T41. In some cases, the position of the amino acids is at F42. In some cases, the position of the amino acids is at K43. In some cases, the position of the amino acids is at F44. In some cases, the position of the amino acids is at Y45. In some cases, the position of the amino acids is at E61. In some cases, the position of the amino acids is at E62. In some cases, the position of the amino acids is at K64. In some cases, the position of the amino acids is at E68. In some cases, the position of the amino acids is at P65. In some cases, the position of the amino acids is in V69. In some cases, the position of the amino acids is at L72. In some cases, the position of the amino acids is at Y107. In some cases, the position of the amino acids is at L72. In some cases, the position of the amino acids is at D109. In some cases, the IL-2 conjugate further comprises an additional mutation. In some cases, the additional mutation is located at an amino acid position selected from K35, T37, R38, T41, F42, K43, F44, Y45, E61, E62, E68, K64, P65, V69, L72 and Y107. In such cases, the amino acid is conjugated with an additional conjugated moiety to increase the half-life of the serum, its stability, or a combination of both. Alternatively, the amino acid first mutates to a naturally occurring amino acid such as lysine, cysteine, histidine, arginine, aspartic acid, glutamic acid, serine, threonine or tyrosine; or to a non-natural amino acid before joining the additional conjugated moiety. In some embodiments, decreasing the affinity of the IL-2 polypeptide modified with an IL-2 α receptor (IL-2Ra) relative to a wild-type IL-2 polypeptide without modification of unnatural amino acids (e.g. a wild-type IL-2 polypeptide) is about 10%, 20%, RczRnn / ίζηζ / Ε / γι 105 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%, or more than 99%. In some cases, the decrease in affinity is approximately 10%. In some cases, the decrease in affinity is approximately 20%. In some cases, the decrease in affinity is approximately 40%. In some cases, the decrease in affinity is approximately 50%. In some cases, the decrease in affinity is approximately 60%. In some cases, the decrease in affinity is approximately 80%. In some cases, the decrease in affinity is approximately 90%. In some cases, the decrease in affinity is approximately 99%. In some cases, the decrease in affinity is greater than 99%. In some cases, the decrease in affinity is approximately 80%. In some cases, the decrease in affinity is approximately 100%. In some embodiments, decreasing the affinity of the IL-2 polypeptide modified with a subunit of the IL-2 receptor α (IL-2Ra) relative to an equivalent IL-2 polypeptide without the unnatural amino acid modification (e.g. , a wild-type IL-2 polypeptide) is about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 30, 50, 100, 200, 300, 400, 500, 1,000 or more times. In some cases, the decrease in affinity is approximately one time. In some cases, the decrease in affinity is approximately 2 times. In some cases, the decrease in affinity is approximately 4 times. In some cases, the decrease in affinity is approximately 5 times. In some cases, the decrease in affinity is approximately 6 times. In some cases, the decrease in affinity is approximately 8 times. In some cases, the decrease in affinity is approximately 10 times. In some cases, the decrease in affinity is approximately 30 times. In some cases, the decrease in affinity is approximately 50 times. In some cases, the decrease in affinity is approximately 100 times. In some cases, the decrease in affinity is approximately 300 times. In some cases, the decrease in affinity is approximately 500 times. In some cases, the decrease in affinity is approximately 1000 times. In some cases, the decrease in affinity is more than 1,000 times. In some cases, the modified IL-2 polypeptide does not interact with IL-2Ra. In some cases, the modified IL-2 polypeptide is further conjugated to a conjugated moiety. In some cases, the IL-2 conjugate does not interact with IL-2Ra. In some embodiments, the modified IL-2 polypeptide exhibits a signaling potency of the first receptor to a Ιί-2βγ signaling complex and a signaling potency of the second receptor to a ΙΕ-2αβγ signaling complex, and wherein the difference between the signaling power of the first receiver and the signaling power of the second receiver is less than 10 times. In some embodiments, the modified IL-2 polypeptide exhibits a signaling potency of the first receptor to a Ιί-2βγ signaling complex and a signaling potency of the second receptor to a Ιί-2αβγ signaling complex, and wherein the difference between the signaling power of the first receiver and the signaling power of the second receiver is less than 5 times. In some cases, the difference is less than 9 times, less than 8 times, less than 7 times, less than 6 times, less than 5 times, less than 4 times, less than 3 times, less than 2 times or less than 1 time. In some cases, the IL-2 polypeptide RczRnn / ίζηζ / Ε / γι Modified 106 is a partial agonist, e.g., an agonist that activates a receptor (e.g., an Iί-2βγ signaling complex or an IΙ_-2αβγ signaling complex), but has only partial efficacy at the receptor relative to a full agonist. In some cases, the modified IL-2 polypeptide is a full agonist, for example, an agonist that activates a receptor (e.g., a Ιί-2βγ signaling complex or a Ιί-2αβγ signaling complex) to a maximal response. In some cases, the signaling power of the receiver is measured with an EC50 value. In some cases, the modified IL-2 polypeptide provides a first EC50 value for activating the IΕ-2βγ signaling complex and a second EC50 value for activating the ΙΕ-2αβγ signaling complex, and wherein the difference between the first EC50 value and the second EC50 value is less than 10 times. In some cases, the modified IL-2 polypeptide provides a first EC50 value for activating the IΕ-2βγ signaling complex and a second EC50 value for activating the ΙΕ-2αβγ signaling complex, and wherein the difference between the first EC50 value and the second EC50 value is less than 5 times. In some cases, the difference is less than 9 times, less than 8 times, less than 7 times, less than 6 times, less than 5 times, less than 4 times, less than 3 times, less than 2 times or less than 1 time. In some cases, the signaling power of the receiver is measured with an ED50 value. In some cases, the modified IL-2 polypeptide provides a first ED50 value for activating the IΕ-2βγ signaling complex and a second ED50 value for activating the ΙΕ-2αβγ signaling complex, and where the difference between the first ED50 value and the second ED50 value is less than 10 times. In some cases, the modified IL-2 polypeptide provides a first ED50 value for activating the ΙΕ-2βγ signaling complex and a second ED50 value for activating the ΙΕ-2αβγ signaling complex, and wherein the difference between the first ED50 value and the second ED50 value is less than 5 times. In some cases, the difference is less than 9 times, less than 8 times, less than 7 times, less than 6 times, less than 5 times, less than 4 times, less than 3 times, less than 2 times or less than 1 time. In some embodiments, the conjugated moiety is linked to the N-terminus or the C-terminus of an IL-2 polypeptide, either directly or indirectly through a linker peptide. In some cases, the conjugated moiety (e.g., a polymer, protein, or peptide) is genetically fused to IL2, at the N-terminus or C-terminus of IL-2, either directly or indirectly through a linker peptide. . In some cases, the conjugated moiety is linked to the N-terminus or the C-terminus of the amino acid residue. In some cases, the conjugated moiety is linked to a reactive group that binds to the N-terminal or C-terminal amino acid residue. In some embodiments, the IL-2 conjugate with reduced binding affinity to IL-2Ra can expand the populations of CD4+ helper cells, naïve effector cells, and CD8+ memory natural killer (NK) cells or natural killer T (NKT) cells. . In some cases, the conjugated fraction impairs or blocks the binding of IL-2 to IL-2Ra. In some cases, the activation of CD4+ helper lymphocyte populations, naïve effector lymphocytes and CD8+ memory natural killer (NK) lymphocytes or natural killer T (NKT) lymphocytes through the IL-2Rβγ complex by the modified IL-2 polypeptide, retains a significant activation potency of said cell population relative to a wild-type IL-2 polypeptide. In some RczRnn / ίζηζ / Ε / γι In 107 cases, activation by the modified IL-2 polypeptide is equivalent to that of the wild-type IL-2 polypeptide. In other cases, activation by the modified IL-2 polypeptide is greater than that of the wild-type IL-2 polypeptide. In some cases, the receptor signaling potency of the modified IL-2 polypeptide to the IL-2R6y complex is greater than that of the wild-type IL-2 polypeptide to the IL2Rpy complex. In some cases, the receptor signaling potency of the modified IL-2 polypeptide is at least one-fold greater than the respective potency of the wild-type IL-2 polypeptide. In some cases, the receptor signaling potency of the modified IL-2 polypeptide is about or at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50 , 60, 70, 80, 90, 100, 150, 200, 300, 400, 500, 1,000 times or more than the respective potency of the wild-type IL-2 polypeptide. In such cases, the dose or concentration of the modified IL-2 polypeptide used to achieve a similar level of activation of the population of CD4+ helper cells, naïve effector cells, and CD8+ memory natural killer (NK) cells or natural killer cells T (NKT) as a wild-type IL-2 polypeptide is lower than the dose or concentration used for the wild-type IL-2 polypeptide. In some embodiments, the activation of CD4+ helper lymphocyte populations, naïve effector lymphocytes and CD8+ memory natural killer (NK) lymphocytes or natural killer T (NKT) lymphocytes by the IL-2Rp complex and by the modified IL-2 polypeptide, retains a significant activation potency of said cell population using a wild-type IL-2 polypeptide. In some cases, the receptor signaling potency of the modified IL-2 polypeptide to the IL-2Rpy complex is less than that of the wild-type IL-2 polypeptide to the IL-2Rpy complex. In some cases, the receptor signaling potency of the modified IL-2 polypeptide is approximately or at least 1,2,3, 4, 5, 10, 20, or 50 times less than the respective potency of the wild-type IL-2 polypeptide. . In some embodiments, the modified IL-2 polypeptide exhibits a first receptor signaling potency to IL-2Rpy and a second receptor signaling potency to IL-2Rapy. In some cases, the first signaling potency of the receptor to IL-2Rpy is an improved potency relative to a wild-type IL-2 polypeptide. In some cases, the second signaling potency of the IL-2Ra8y receptor is a decreased potency relative to the wild-type IL-2 polypeptide. In some embodiments, the modified IL-2 polypeptide exhibits a first receptor signaling pot...

Claims

1. An IL-2 conjugate comprising the amino acid sequence of SEQ ID NO: 3, wherein at least one amino acid residue in the IL-2 conjugate at an amino acid position selected from K35, F42, F44, K43, E62, P65, R38, T41, E68, Y45, V69 and L72 with reference to the amino acid positions within SEQ ID NO: 1 is replaced by the structure of Formula (I): RczRnn / ίζηζ / E / γι Formula (I); wherein: ψ'HZ is CH2 and Y is 0 0; Ϩ'HY is CH2 and Z is 0 0; ψ*o Z is CH2 and Y is θ; or ψ-OY is CH2 and Z is θ; W is a PEG group having a selected average molecular weight of 5 kDa, 10 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 35 kDa, 40 kDa, 45 kDa, 50 kDa and 60 kDa; and X has the structure: either a pharmaceutically acceptable salt, solvate or hydrate thereof.

2. The IL-2 conjugate according to claim 1, wherein W is a PEG group having an average molecular weight selected from 5 kDa, 10 kDa, 20 kDa and 30 kDa or a pharmaceutically acceptable salt, solvate or hydrate thereof.

3. The IL-2 conjugate according to claim 2, wherein W is a PEG group having an average molecular weight of 5 kDa or a pharmaceutically acceptable salt, solvate or hydrate thereof.

4. The IL-2 conjugate according to claim 2, wherein W is a PEG group having an average molecular weight of 30 kDa or a pharmaceutically acceptable salt, solvate or hydrate thereof.

5. The IL-2 conjugate according to claim 1, wherein the IL-2 conjugate comprises the amino acid sequence of any of SEQ ID NO: 45 to 49, wherein [AzK_L1_PEG5kD] has the structure of Formula (IV) or Formula (V) or a mixture of Formula (IV) and Formula (V): RczRnn / ίζηζ / E / γι Formula (IV); Formula (V); wherein: W is a PEG group having an average molecular weight of 5 kDa; and X has the structure: Xl| / \,NH oZ*+i| or a pharmaceutically acceptable salt, solvate, or hydrate thereof.

6. The IL-2 conjugate according to claim 5, wherein the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 45, or a pharmaceutically acceptable salt, solvate or hydrate thereof.

7. The IL-2 conjugate according to claim 5, wherein the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 46, or a pharmaceutically acceptable salt, solvate, or hydrate thereof. 344 8. The IL-2 conjugate according to claim 1, wherein the IL-2 conjugate comprises the amino acid sequence of any of SEQ ID NO: 50 to 54, wherein [AzK_L1_PEG30kD] has the structure of Formula (IV) or Formula (V) or a mixture of Formula (IV) and Formula (V): RczRnn / ίζηζ / E / γι Formula (IV); Formula (V); wherein: W is a PEG group having an average molecular weight of 30 kDa; and X has the structure: | x-11 / \.NH Q^^lx+ilL or a pharmaceutically acceptable salt, solvate, or hydrate thereof.

9. The IL-2 conjugate according to claim 8, wherein the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 50, or a pharmaceutically acceptable salt, solvate or hydrate thereof.

10. The IL-2 conjugate according to claim 8, wherein the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 51, or a pharmaceutically acceptable salt, solvate or hydrate thereof.

11. The IL-2 conjugate according to claim 8, wherein the IL-2 conjugate has the amino acid sequence of SEQ ID NO: 52, or a pharmaceutically acceptable salt, solvate or hydrate thereof.

12. The IL-2 conjugate according to claim 8, wherein [AzK_L1_PEG30kD] has the structure of Formula (IV): RczRnn / Lznz / B / Yi Formula (IV); or a pharmaceutically acceptable salt, solvate or hydrate thereof.

13. The IL-2 conjugate according to claim 8, wherein [AzK_L1_PEG30kD] has the structure of Formula (V): Formula (V); or a pharmaceutically acceptable salt, solvate or hydrate thereof.

14. A method for treating cancer in a subject comprising administering to a subject in need an effective amount of an IL-2 conjugate according to any one of claims 1 to 13.

15. The method according to claim 14, wherein the cancer is selected from the group consisting of renal cell carcinoma (RCC), melanoma, non-small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC), urothelial carcinoma (UC), Merkel cell carcinoma (MCC), ovarian cancer, gastric cancer, and breast cancer.