Hematopoietic prostaglandin synthase (HPGDS) inhibition for treating cancer

Abstract

The disclosure relates to the medical use of inhibitors of expression or function of the hematopoietic prostaglandin synthase (HPGDS) in the treatment of cancer in general or more in particular in the treatment of cancer in which HPGDS is predominantly expressed by tumor-associated macrophages in the tumor micro-environment. Inhibition of HPGDS as enhancer of immune checkpoint inhibitor therapy is also disclosed, as are (companion) diagnostic methods. The disclosure further relates to isolated macrophages in which HPGDS expression or function is inhibited, such as for medical use.

Description

[0001]MaMa / HPGDS / 822 Hematopoietic prostaglandin synthase (HPGDS) inhibition for treating cancer FIELD OF THE INVENTIONThe disclosure relates to the medical use of inhibitors of expression or function of the hematopoieticprostaglandin synthase (HPGDS) in the treatment of cancer in general or more in particular in thetreatment of cancer in which HPGDS is predominantly expressed by tumor-associated macrophages in the tumor micro-environment. Inhibition of HPGDS as enhancer of immune checkpoint inhibitor therapyis also disclosed, as are (companion) diagnostic methods. The disclosure further relates to isolatedmacrophages in which HPGDS expression or function is inhibited, such as for medical use. BACKGROUND TO THE INVENTIONProstaglandin D2 (PGD2; CAS No 41598-07-6), an arachidonic acid metabolite produced byhematopoietic PGD synthase (H-PGDS or HPGDS) and by lipocalin-type PGD Synthase (L-PGDS or LPGDS),is mainly interacting with two receptors: DP1 (DP, PTGDR1) and DP2 (CRTH2, PTGDR2, CD294).About 90% of PGD2 is believed to be produced through HPGDS. Hematopoietic Prostaglandin D2signaling has been explored as a therapeutic target for treating allergic diseases including allergicasthma, rhinitis, atopic dermatitis, food allergy, gastrointestinal allergic disorder, and anaphylaxis; andseveral small molecule HPGDS inhibitors have been reported (reviewed in e.g. Beura and Chetti 2022, J Mol Structure 1259:132704).The effect on tumor growth of meddling with the HPGDS – PGD2 -DP1 / DP2 signaling pathway has mostlybeen documented for Lewis lung cancer (LLC) and B16 melanoma (B16). Growth of subcutaneousimplanted LLC and B16 was reported to be promoted by knock-down or inhibition of HPGDS and to beinhibited by DP1 agonism whereas DP2 knock-down or inhibition had no effect (Murata et al.2011, PNAS108 (49):19802-19807; WO2017 / 209272). On the other-hand, in a metastasis model of either LLC or B16 (via intravenous injection of tumor cells), inhibition of metastasis was reported by knock-down or inhibition of HPGDS and by knock-down or inhibition of DP2 whereas DP1 knock-down had no effect (data only for B16) (Murata et al.2008, PNAS 105(50):20009-14; Omori et al.2018, J Pathol 244 (1):84-96; WO2017 / 209272; Mary et al.2022, Cancer Immunol Res 10:900–916). PGD2 itself was reported to inhibit gastric cancer whereas DP2 knock-down promoted growth (CN106619651; Zhang et al.2018, Stem Cells 36:990–1003; subcutaneous cancer model). Knock-downof HPGDS was further reported to promote intestinal adenomas (Park et al. 2007, Cancer Res 67:881),whereas treatment of leukemia with an agonist of a prostaglandin D receptor (DP1 or DP2) was claimedin US9623031. MaMa / HPGDS / 822Mary et al.2022 (Cancer Immunol Res 10:900–916) reported on the possible involvement of T follicularhelper (Tfh) cells in HPGDS / CRTH2-mediated tumor metastasis, and on the combination of anti-IL4 antibodies with inhibition of HPGDS.In the setting of acute promyelocytic leukemia, Trabanelli et al.2017 (Nat Commun 8:593) described animmunosuppressive mechanism implying in part activation of group 2 innate lymphoid cells (ILC2s) byPGD2 via CRTH2 on ILC2s, in turn activating monocytic myeloid-derived suppressor cells (M-MDSCs).SUMMARY OF THE INVENTIONThis disclosure relates to inhibitors of hematopoietic prostaglandin D synthase (HPGDS) for use intreating a tumor or cancer, inhibiting a tumor or cancer, or inhibiting progression of a tumor or cancer.In particular, such tumor or cancer is a primary tumor or cancer.In one embodiment, the inhibitor of HPGDS is for use in treating or inhibiting (progression of) a tumor or cancer in combination with immune checkpoint inhibitor therapy, wherein the tumor or cancer is poorly responding or non-responsive to immune checkpoint inhibitor therapy.This disclosure also relates to inhibitors of HPGDS for use in potentiating treatment with an immunecheckpoint inhibitor of a tumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy. In any of the above, the tumor or cancer micro-environment of the tumor or cancer in particular is characterized in that the total amount of expression of HPGDS in the tumor micro-environmentcompartment is predominantly contributed by tumor- or cancer-associated macrophages.In any of the above, the inhibitor of HPGDS more in particular is selectively inhibiting function or expression of HPGDS. In any of the above, the inhibitor of HPGDS is combined with a further anti-tumor or anti-cancer agent, and / or in combination with surgery or radiation. This disclosure furthermore relates to isolated macrophages substantially lacking functional HPGDS, to isolated HPGDS knock-out macrophages, or to isolated macrophages conditionally expressing an inhibitor of HPGDS. Such macrophages can in particular be CAR-macrophages or TCR-macrophages. Such macrophages in particular are for use as a medicament. This disclosure furthermore relates to combinations of an immune checkpoint inhibitor and an inhibitorof HPGDS, an isolated macrophage substantially lacking functional HPGDS, an isolated HPGDS knock-outmacrophage, and / or an isolated macrophage conditionally expressing an inhibitor of HPGDS. Suchcombinations in particular are for use as a medicament.This disclosure furthermore relates to methods for selecting a subject having cancer for therapy includingan inhibitor of HPGDS, an isolated macrophage substantially lacking functional HPGDS, an isolated MaMa / HPGDS / 822 HPGDS knock-out macrophage or an isolated macrophage conditionally expressing an inhibitor ofHPGDS, comprising: assessing the expression of HPGDS in a tumor biopsy sample obtained from thesubject, and selecting a subject having cancer for therapy including an inhibitor of HPGDS, an isolatedmacrophage substantially lacking functional HPGDS, an isolated HPGDS knock-out macrophage or anisolated macrophage conditionally expressing an inhibitor of HPGDS, when the total amount ofexpression of HPGDS in the tumor micro-environment compartment of the tumor biopsy ispredominantly contributed by or occurring in tumor- or cancer-associated macrophages.This disclosure furthermore relates to methods for determining response of subject having cancer toimmune checkpoint inhibitor therapy or to therapy including an immune checkpoint inhibitor,comprising: assessing the expression of HPGDS in an on-therapy tumor biopsy sample obtained from thesubject, and determining the subject to respond to immune checkpoint inhibitor therapy or to therapyincluding an immune checkpoint inhibitor when the level of HPGDS expression in the on-therapy tumorbiopsy sample corresponds to reference on-therapy tumor biopsy sample HPGDS expression levels thatare indicative of response of a subject having the cancer to the therapy including an ICI or to the therapywith an ICI.BRIEF DESCRIPTION OF THE DRAWINGSFIGURE 1. Identification of HPGDS expression on immunosuppressive TAMs(A) HPGDS expression in the immune cells from an in-house single-cell RNA-Seq dataset of melanomapatients.(B) Violin plot from an in house single-cell RNA-Seq dataset showing the expression of HPGDS in differentmacrophage subsets.(C) Violin plot from an in house single-cell RNA-Seq dataset of HPGDS expression in M1-and M2-likemacrophages of melanoma patients.(D) Correlation analysis of HPGDS high M2-like macrophages with activated CD8+ T cells of humanmelanoma tumors. (E) Co-localization of the monocyte / macrophage-specific CD68 marker and HPGDS in primary tumor, lymph node and liver metastatic site.P value was assessed by two sided Wilcoxon test (C) and Spearman’s rank correlation test (D).FIGURE 2. Hpgds inhibition re-educates macrophages towards an anti-tumoral M1-like phenotype(A) qRT-PCR analysis of the expression of Hpgds in cultured YUMM 1.7 CD90.1+ melanoma cancer cells(“YUMM (in vitro)”), or in cells sorted from a YUMM 1.7 tumor: YUMM 1.7 CD90.1+ cancer cells (CD45-,CD90.1+; “YUMM (in vivo)”), CAFs (CD45-, CD90.2+), ECs (CD45-, CD31+), CD8+ T cells (CD45+, CD11b-, CD4- MaMa / HPGDS / 822 , CD8+), CD4+T cells (CD45+, CD11b-, CD8-, CD4+), TAMs (CD45+, CD11b+, F4 / 80+), TANs (CD45+, F4 / 80-, Ly6G+), DCs (CD45+, F480-, MHC-IIhigh, CD11c+) and Mast cells (CD45+, CD117+, FceR1+). (B) Representative images of YUMM 1.7 tumor sections stained for Hpgds and F480; CD31; CD8 or CD4. Nuclei are stained with Hoechst.(C) qRT-PCR analysis of the expression of Hpgds in in vitro polarized BMDMs and sorted TAMs (CD45+,CD11b+, F4 / 80+). (D) FACS analysis of the expression of M1 (CD11c) or M2 (CD206) polarization markers in M2-likemacrophages in which siHpgds was introduced (Hpgds expression silenced), or in which a scramble siRNAwas introduced (Hpgds expression not silenced).(E) HPGDS expression assessed by qRT-PCR in human monocyte derived macrophages (hMDMs)differentiated into M0, M1 or M2-like macrophages. (F) Expression assessed by qRT-PCR of M1 (CXCL10) and M2 (CD206) polarization markers in M2-likehMDMs in which siHpgds was introduced (Hpgds expression silenced), or in which a scramble siRNA wasintroduced (Hpgds expression not silenced).(G) Intracellular abundance of PGD2 measured by LC / MS in macrophages in which siHpgds wasintroduced (Hpgds expression silenced), or in which a scramble siRNA was introduced (Hpgds expressionnot silenced). (H) FACS analysis of the expression of M1 (CD80) or M2 (CD206) polarization markers in bone marrow derived macrophages (BMDMs) treated for 48hr with 1 µM PGD2.(I-K) Quantification of the total sprout length (I), number of sprouts (J), and representative images (K) ofHUVECs spheroids embedded in collagen I (“HUVEC”) and of HUVEC spheroids co-incubated withBMDMs in which siHpgds was introduced (Hpgds expression silenced; “siHpgds”), or in which a scramblesiRNA was introduced (Hpgds expression not silenced; “scramble”).(L) VEGFC and VEGFA expression over time assessed by qRT-PCR in HUVECs treated with 1 µM PGD2.(M) Quantification of HUVEC migration through BMDMs (seeded on 8 um pore-transwell). Prior to the assay, HUVECs were incubated for 48hr with 1 µM PGD2.P value was assessed by unpaired, two-tailed Student’s t-test (D, F; G, H, M) or one-way ANOVA (C, I, J;L). All graphs show mean ± SEM.(N) FACS analysis of the expression of M1 (CD11c) or M2 (CD206) polarization markers in M0-likemacrophages in which siHpgds was introduced (Hpgds expression silenced), or in which a scramble siRNAwas introduced (Hpgds expression not silenced).(O) qRT-PCR analysis of the analysis of the expression of M1 (CXCL10) or M2 (CD206) polarizationmarkers in human macrophages in which siHpgds was introduced (Hpgds expression silenced), or inwhich a scramble siRNA was introduced (Hpgds expression silenced). MaMa / HPGDS / 822 (P) Arachidonic acid and thromboxane B2 abundance measured by LC / MS in scramble or siHpgds BMDMs.(Q) qRT-PCR analysis of the expression of Lpgds (lipocalin-type prostaglandin D synthase) in culturedYUMM 1.7 CD90.1+ melanoma cancer cells (“YUMM (in vitro)”), or in cells sorted from a YUMM 1.7tumor: YUMM 1.7 CD90.1+ cancer cells (CD45-, CD90.1+; “YUMM (in vivo)”), CAFs (CD45-, CD90.2+), ECs(CD45-, CD31+), CD8+T cells (CD45+, CD11b-, CD4-, CD8+), CD4+T cells (CD45+, CD11b-, CD8-, CD4+), TAMs (CD45+, CD11b+, F4 / 80+), TANs (CD45+, F4 / 80-, Ly6G+), DCs (CD45+, F480-, MHC-IIhigh, CD11c+) and Mast cells (CD45+, CD117+, FceR1+).P value was assessed by unpaired, two-tailed Student’s t-test (N-P). All graphs show mean ± SEM.FIGURE 3. Hpgds deletion in TAMs potently inhibits tumor growth and reshapes the TME(A) Tumor growth (left panel) and tumor weight (right panel) in WT^WT and Hpgds KO^ WT chimeras(see Example 3).(B-D) FACS analysis of total TAMs (B), M1- (MHC-IIhigh, CD11c and CD86) (C) and M2- (MHC-IIlow, CD206,CD204) (D) polarization markers in WT^WT and Hpgds KO^ WT chimeras (see Example 3).(E) Quantification of F480, CD80 or CD206 staining in WT^WT and Hpgds KO^ WT chimeras (seeExample 3). (F-G) Flow cytometric quantification of CD8+T cells (F) and activated CD8+T cells (CD8+IFNγ+; CD8+GZMB+)(G) in WT^WT and Hpgds KO^ WT chimeras (see Example 3).(H) Quantification of CD8+ T cells infiltration in the tumor core in WT^WT and Hpgds KO^ WT chimeras(see Example 3).(I) qRT-PCR analysis of the expression of Hpgds in cells sorted from a YUMM 1.7 tumor: YUMM 1.7CD90.1+cancer cells (CD45-, CD90.1+; “YUMM (in vivo)”), CAFs (CD45-, CD90.2+), ECs (CD45-, CD31+), CD8+T cells (CD45+, CD11b-, CD4-, CD8+), CD4+T cells (CD45+, CD11b-, CD8-, CD4+), TAMs (CD45+, CD11b+, F4 / 80+), TANs (CD45+, F4 / 80-, Ly6G+), DCs (CD45+, F480-, MHC-IIhigh, CD11c+) and Mast cells (CD45+,CD117+, FceR1+) from control mice (“Ctrl”; left bars for each cell type on the X-axis) and Hpgds KO mice(right bars for each cell type on the X-axis).P value was assessed by unpaired, two-tailed Student’s t-test (A, right panel; B-G), two-way ANOVA (A,left panel) or paired, two-tailed Student’s t-test (H). All graphs show mean ± SEM.(J) Tumor growth (left panel) and tumor weight (right panel) of YUMM 1.7-melanoma bearing miceimplanted in CD64-Cre;Hpgds+ / +or CD64-Cre;HpgdsL / Lmice. (K-M) FACS analysis of the percentage of TAMs (CD45+, CD11b+, F480+) (K) and of the expression of different M1 (MHC-IIhigh, CD11c, CD86) (L) or M2 (MHC-IIlow, CD206, CD204) (M) polarization markersfrom CD64-Cre; Hpgds+ / + or CD64-Cre; HpgdsL / L YUMM 1.7 melanoma bearing mice. MaMa / HPGDS / 822 (N) Quantification of melanoma tumors of Ctrl and Hpgds-KO sections stained for F480, CD80 (M1- polarization marker) or CD206 (M2-polarization marker). (O-P) FACS analysis of the percentage (O) and activation (CD69, IFNγ and GZMB) (P) of CD8+T cells in melanoma tumors of Ctrl and Hpgds-KO mice.(Q) Quantification of vessel size (based on quantification of CD105+ cells), perfused vessels (based onquantification of lectin-FITC+ cells), pericyte blood vessel coverage (based on quantification of αSMA+cells), and of hypoxic region in (based on quantification of PIMO+ cells) in YUMM 1.7 melanoma tumorsof Ctrl and Hpgds-KO mice. (R) Extracellular levels of PGD2, Arachidonic Acid (AA) and PGE2in the interstitial fluid of melanoma tumors of Ctrl and Hpgds-KO mice.(S) Intratumoral concentration of PGD2 measured by LC / MS in melanoma bearing mice Hpgds WT andKO. (T), quantification of the number of YUMM 1.7 melanoma cancer cells migrated towards macrophages (Ctrl or Hpgds-KO).(U) FACS analysis (left panel) and qRT-PCR analysis (right panel) of the percentage of CD90.1+ cells (outof viable) in the blood collected from Ctrl and HpgdsΔMø(Hpgds-KO ) YUMM 1.7-melanoma bearing mice(n = 3 for FACS; n = 5 for qRT-PCR).P value was assessed by unpaired, two-tailed Student’s t-test (J, right panel; K-N, O-S, U) or two-wayANOVA (J, left panel). All graphs show mean ± SEM.FIGURE 4. The mechanism of tumor regression mediated by Hpgds inhibition is driven by macrophagesand CD8+T cells (A-B) Tumor growth (A), tumor weight (B) of YUMM 1.7 CD90.1+melanoma tumors injected in CD64-Cre;Hpgds+ / + (“Ctrl”) mice or CD64-Cre;HpgdsL / L (“Hpgds-KO”) mice and treated with an irrelevant IgGantibody (“IgG”) or anti-CD8 antibody / CD8-depleting antibody (“αCD8”).(C) Quantification of vessel size (based on quantification of CD105+ cells) and pericyte blood vesselcoverage (based on quantification of αSMA+ cells) in melanoma tumors of Ctrl and Hpgds-KO micetreated with an irrelevant IgG antibody (“IgG”) or anti-CD8 antibody / CD8-depleting antibody (“αCD8”). (D) FACS analysis of IFNg+CD8+T cells and TNFa+CD8+T cells upon co-culture with Ctrl or Hpgds-KO BMDMs.(E) qRT-PCR analysis for CD90.1 in lungs collected from Ctrl and Hpgds-KO (HpgdsΔMø) melanoma-bearingmice treated with IgG or αCD8 antibody (n = 3 – 4).(F-G) Tumor growth (F) and weight (G) from Ctrl and HpgdsΔMø tumor-bearing mice treated with IgG orαPD1 when the average tumor of the group was 150 mm3(tumors from 2 out of 13 HpgdsΔMømice did not reach 150 mm3, thus, excluded from the experiment). MaMa / HPGDS / 822P value was assessed by unpaired, two-tailed Student’s t-test (C, D), two-way ANOVA (A) , one-wayANOVA (B), two-way repeated measures ANOVA (F), or two-way ANOVA with Turkey’s multiplecomparison test (E, G). All graphs show mean ± SEM.FIGURE 5: Pharmacologic inhibition of Hpgds inhibits tumor growth and re-educates macrophagestowards an M1-like phenotype(A) Tumor growth (left panel) and tumor weight (right panel) of YUMM 1.7 CD90.1+ melanoma tumorbearing mice treated by oral gavage with HQL-79, 30 mg / kg BID or with vehicle control. (B) Left panel: fold change of the expression of M1 (CD80 and CXCL10) and M2 (Arg1 and CD206) markers in TAMs sorted from mice treated with HQL-79 versus vehicle treated mice. Right panel: Quantification of CD80 or CD206 staining in melanoma tumors of vehicle or HQL-79 treated mice.(C) Tumor growth (left panel) and tumor weight (right panel) of NrasQ61K; Ink4A- / - melanoma tumorbearing mice treated by oral gavage with vehicle or with HQL-7930 mg / kg BID. (D-E) Quantification of the number (D) and size (E) of the micro-and macro-nodules of HCC bearing mice treated by oral gavage with HQL-7930 mg / kg BID or with vehicle. (F) Quantification of F4 / 80 and CD206 staining in HCC tumors of vehicle or HQL-79 treated mice.(G) FACS analysis (n = 6; left panel) and qRT-PCR analysis (n = 5 – 6; right panel) of YUMM 1.7 CD90.1+cancer cell intravasation into the bloodstream (left panel) or in lungs (right panel) in melanoma-bearingmice treated by oral gavage with HQL-79 or with vehicle control (n = 6).(H) Tumor growth (left panel) and tumor weight (right panel) of YUMM 1.7 CD90.1+melanoma-bearingCtrl or HpgdsΔMø-ERT2 mice treated with vehicle or HQL-79 (n = 4).(I) Tumor growth (left panel) and tumor weight (right panel) of YUMM 1.7 CD90.1+melanoma-bearingmice treated by oral gavage with Cmpd1y 0.1 – 0.3 – 1 – 3 mg / kg BID or with vehicle (n = 7 – 9). Datashows a pool of two independent experiments. (J) Tumor growth of YUMM 1.7 CD90.1+melanoma-bearing mice treated by oral gavage with TAS-20530mg / kg BID or vehicle (n = 9).(K) Calcein area of patient-derived organotypic tumor spheroids (PDOTs) treated with 1 µM HQL-79 or with vehicle control for 72hr.P value was assessed by unpaired, two-tailed Student’s t-test (A-E), one-way ANOVA (F-G), unpaired,two-tailed Student’s t-test (H), two-way repeated measures ANOVA (L), multiple unpaired Student’s t-test (left panel of H; left panel of I; J), or two-way ANOVA with Turkey’s multiple comparison test (rightpanel of H), one-way ANOVA with Turkey’s multiple comparison test (right panel of H). All graphs showmean ± SEM. MaMa / HPGDS / 822FIGURE 6: HPGDS systemic inhibition improves ICB efficacy.(A) Violin plot from an in house single-cell RNA-Seq dataset showing the expression of HPGDS inmelanoma patients before and during the treatment with α-PD1 stratified in responders and non- responders.(B) Tumor volume (left panel) and tumor weight (right panel) of GEM mice BrafV600EPten- / - in mice treatedwith vehicle as control or with HQL-7930 mg / kg BID. (C) FACS analysis of the expression of CD11c+macrophages (M1-like) in GEM mice BrafV600EPten- / -treated with HQL-79 or with vehicle. (D-E) Flow cytometric quantification of CD8+T cells (D) and PD-1 expressing CD8+T cells (E) in GEM mice BrafV600EPten- / -treated with vehicle or with HQL-79. (F) Tumor volume (left panel) and tumor weight (right panel) of GEM BrafV600EPten- / -mice treated with vehicle, HQL-7930 mg / kg BID, α-PD1 or the combination of HQL-79 and α-PD1.(G) Left panel: percentage of M1- like macrophages (CD11c+) in GEM mice BrafV600EPten- / - mice treatedwith vehicle, HQL-79, α-PD1 or HQL-79 in combination with and α-PD1. Right panel: Flow cytometric quantification of CD8+T cells (D) and PD-1 expressing CD8+T cells (E) in GEM mice BrafV600EPten- / -treated with vehicle, HQL-79, α-PD1 or HQL-79 in combination with and α-PD1.(H) Tumor weight of KPC FC1245 PDAC-bearing mice treated with vehicle / IgG, HQL-79, αPD1, or HQL-79in combination with αPD1 (n = 11 – 16).P value was assessed by unpaired, two-tailed Student’s t-test (A-E), one-way ANOVA (F-G), or two-wayrepeated measures ANOVA (H). All graphs show mean ± SEM.FIGURE 7. Expression of HPGDS in the B16 melanoma tumor micro-environment. HPGDS ispredominantly expressed (visible as black dots) in malignant cells and alveolar cells 1, with furtherscattered expression in NK cells, B cells, and monocytes / macrophages. DETAILED DESCRIPTIONIn work leading to the current disclosure, it was observed that inhibition of the expression or activity ofhematopoietic prostaglandin D2 synthase (HPGDS) led to inhibition of tumor growth. As initial model, the YUMM1.7 melanoma tumor was studied. These results contradict literature reporting promotion ofB16 melanoma tumor growth following inhibition of HPGDS. An explanation for these contradicting wassubsequently found in the observation that HPGDS expression in the tumor micro-environment (TME)of YUMM1.7 melanoma tumors is largely restricted to tumor-associated macrophages (TAMs). HPGDSexpression in the TME of B16 melanoma, however, was largely in malignant cells (and in other cells),much more than in TAMs (and no co-localization of HPGDS expression with TAMs could be observed byimmunohistochemistry). A further tumor model, hepatocellular carcinoma (HCC), was also studied and MaMa / HPGDS / 822shown to be sensitive to HPGDS inhibition; expression of HPGDS in the TME was likewise largelyrestricted to TAMs. The anti-tumoral activity of HPGDS inhibition was shown to be dependent on CD8+T-cell infiltration. Working further on the above, it was found that tumors of human cancer patients not responding toimmune checkpoint blockers or inhibitors (ICBs or ICIs) were characterized by maintained highexpression of HPGDS in TAMs, whereas tumors of ICB-responsive patients had TAMs with low expressionof HPGDS. In mouse tumor models poorly responsive or non-responsive to either HPGDS inhibitor or ICBtherapy, such HPGDS inhibition did sensitize the tumor to ICBs and synergistic tumor growth inhibition was observed.Thus, predominant expression in TAMs in the TME of a tumor is a criterion for selecting patients havingcancer (e.g. naïve tumor, or tumor treated with ICI but poorly or non-responding to ICI therapy) for therapy / additional therapy with an inhibitor of HPGDS.Furthermore, HPGDS expression levels in TAMs of a cancer patient responding to ICI therapy wassignificantly reduced on-treatment versus pre-treatment. On-treatment HPGDS expression levels inTAMs of a cancer patient not or poorly responding to ICI therapy in contrast was similar to pre-treatmentHPGDS expression levels in TAMs. HPGDS expression in TAMs therefore can serve as biomarker for earlyresponse of a cancer patient to ICI therapy. HPGDSHematopoietic prostaglandin D2 synthase or HPGDS is an enzyme (EC:5.3.99.2, EC:2.5.1.18) also knownas glutathione-dependent PGD synthase, GSTS, PGDS or PTGDS2. The human HPGDS gene is located onchr4:94,298,535-94,342,876 (GRCh38 / hg38; minus strand), on chr4:95,219,686-95,263,987(GRCh37 / hg19 by NCBI Gene; minus strand), or on chr4:95,219,686-95,264,027 (GRCh37 / hg19 byEnsembl; minus strand). The human HPGDS protein is identified by UniProt accession No. O60760,Ensembl accession No. ENSP00000295256, and NCBI reference sequences with accession Nos.XP_005262989.1, XP_054205671.1, and NP_055300.1. The NCBI reference mRNA sequence for humanHPGDS is identified by accession No. NM_014485.3. Inhibition of HPGDS activity or expressionSeveral HPGDS inhibitors are known, including small molecules such as HQL-79 (CAS No 162641-16-9;e.g. Aritake et al.2006, J Biol Chem 281:15277-15286), TFC-007 (CAS No 927878-49-7; Nabe et al.2011,Prostaglandins & Other Lipid Mediators 95: 27-34), hPGDS inhibitor I (CAS No 1033836-12-2; Pellefigueset al. 2018, Nat Commun 9 :725), TAS-204 (Kajiwara et al.2011, Eur J Pharmacol 667:389-395, ZL-2102(classic.clinicaltrials.gov / ct2 / show / NCT02397005), TAS-205 (TAS-205 free-base: pizuglanstat, CAS No MaMa / HPGDS / 822 1244967-98-3; Takeshita et al.2018, Ann Clin Transl Neurol 5:1338–1134), KMN-698 (Maric et al.2018,J Allergy Clin Immunol 143:2202–2214), and SP1, SP2, SP5 and SP10 (Beura and Chetti 2022, J MolStructure 1259:132704).A HPGDS degradation inducing proteolysis targeting chimera (PROTAC) has been reported recently byYokoo et al.2021 (ACS Med Chem Lett 12: 236-241).The experimental work outlined herein further supports that inhibition of HPGDS expression isobtainable by means of targeted inhibition or genetic knock-out of HPGDS in macrophages, or by meansof siRNAs targeting HPGDS. Inhibitory RNAs (e.g. Origene Catalog No TL315682V, HPGDS Human shRNALentiviral Particle; Santa Cruz Catalog No sc-41638, siRNA; Santa Cruz Catalog No sc-41638-SH, plasmidshRNA) and guide RNAs for use with CRISPR-Cas (e.g. ABM Catalog No 23862111as lentiviral set; ABMcatalog No 23862151 as AAV set; Origene Catalog No GA109114, Human HPGDS activation kit by CRISPR)are furthermore commercially available. Medical uses, methods and products In view of the above, the present disclosure defines a number of aspects and embodiments thereto.A first series of aspects relate to the medical use of inhibitors of HPGDS / HPGDS inhibitors. In general, asan alternative for “inhibitor”, the terms “blocker”, “antagonist”, “inactivating compound”, “repressor”or “suppressor” can be used.More in particular, a first aspect of this disclosure relates to an inhibitor of hematopoietic prostaglandinD synthase (HPGDS) for use in treating a tumor or cancer, inhibiting (growth of) a tumor or cancer, orinhibiting progression of a tumor or cancer or of progression of tumor or cancer growth. Alternatively,this aspect relates to an inhibitor of hematopoietic prostaglandin D synthase (HPGDS) for use in themanufacture of a medicament for treating a tumor or cancer, for inhibiting (growth of) a tumor or cancer,or for inhibiting progression of a tumor or cancer or of progression of tumor or cancer growth. A furtheralternative relates to methods of treating a (subject having) a tumor or cancer, of inhibiting (growth of)a tumor or cancer (in a subject having a tumor or cancer), or of inhibiting progression of a tumor orcancer or of progression of tumor or cancer growth (in a subject having a tumor or cancer), such methodsincluding administering a (therapeutically effective dose of a) HPGDS inhibitor to the subject having atumor or cancer. With this administering the tumor or cancer is treated or inhibited, or its progressionis inhibited.In one embodiment to this alternatives, the tumor or cancer is a primary tumor or cancer. In a notmutually exclusive embodiment, the tumor or cancer is a solid tumor or cancer. MaMa / HPGDS / 822In another, not mutually exclusive embodiment to this alternatives, the inhibitor of HPGDS is combinedwith immune checkpoint inhibitor therapy. More in particular hereto, the tumor or cancer is poorly responding or non-responsive to immune checkpoint inhibitor monotherapy.A second aspect of this disclosure relates to an inhibitor of HPGDS for use in potentiating treatment withor including an immune checkpoint inhibitor therapy of a tumor or cancer that is poorly responding ornon-responsive to immune checkpoint inhibitor therapy. Alternatively, the inhibitor of HPGDS is for usein the manufacture of a medicament for use in potentiating treatment with or including an immune checkpoint inhibitor therapy of a tumor or cancer that is poorly responding or non-responsive to immunecheckpoint inhibitor therapy. A further alternative relates to methods of treating a (subject having a)tumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy (ortherapy comprising an immune checkpoint inhibitor), such methods including potentiating tumor or cancer treatment or therapy with or including an immune checkpoint inhibitor by administering (atherapeutically effective dose of) an inhibitor of HPGDS to the subject having a tumor or cancer.Alternatively such methods include sensitization of the subject having a tumor or cancer to immunecheckpoint inhibitor (comprising) therapy. With administering the HPGDS inhibitor, the tumor or canceris sensitized to the immune checkpoint inhibitor (therapy), or the immune checkpoint inhibitor therapy is potentiated. Vice versa, this disclosure relates to an immune checkpoint inhibitor for use in potentiating treatmentwith or including an inhibitor of HPGDS of a tumor or cancer that is poorly responding or non-responsiveto an inhibitor of HPGDS. Alternatively, the immune checkpoint inhibitor is for use in the manufactureof a medicament for use in potentiating treatment with or including an inhibitor of HPGDS of a tumor orcancer that is poorly responding or non-responsive to an inhibitor of HPGDS. A further alternative relatesto methods of treating a (subject having a) tumor or cancer that is poorly responding or non-responsiveto an inhibitor of HPGDS (or therapy comprising an inhibitor of HPGDS), such methods includingpotentiating tumor or cancer treatment or therapy with or including an inhibitor of HPGDS byadministering (a therapeutically effective dose of) an immune checkpoint inhibitor to the subject having a tumor or cancer. Alternatively such methods include sensitization of the subject having a tumor orcancer to an inhibitor of HPGDS therapy. With administering the immune checkpoint inhibitor, the tumoror cancer is sensitized to the inhibitor of HPGDS, or the HPGDS inhibitor therapy is potentiated.In one (further) embodiment to the above aspects and embodiments, the tumor or cancer micro-environment (TME) or TME compartment of the tumor or cancer is characterized in that HPGDSexpression is limited to expression in tumor- or cancer-associated macrophages (TAMs), or in that HPGDS MaMa / HPGDS / 822is selectively expressed in TAMs compared to in other cells of the TME or TME compartment.Alternatively, the TME or TME compartment of the tumor or cancer is characterized in that the totalamount of expression of HPGDS in the TME or TME compartment ismainly / predominantly / primarily / quantitatively selectively contributed by tumor- or cancer-associatedmacrophages or occurring in tumor- or cancer-associated macrophages. Alternatively, the TME or TMEcompartment of the tumor or cancer is characterized in that the tumor- or cancer-associatedmacrophages in the TME are the main / predominant / primary / quantitatively selective contributors to thetotal amount of expression of HPGDS in the TME or TME compartment of the tumor or cancer. In furtherexplanation hereof, it may be that HPGDS is expressed in different cell types present in the TME or TMEcompartment, all together constituting the total amount of expression of HPGDS in the TME or TMEcompartment (as could e.g. be determined by bulk RNA sequencing of nucleic acids isolated from anobtained tumor or cancer biopsy sample, or by immunohistochemistry, or by spatial expressiondetection techniques). In this case and in the current context, the majority of the HPGDS expressionshould be detected in the TAMs present in the TME or TME compartment / tumor or cancer biopsy sample(as could e.g. be determined by single cell RNA sequencing of nucleic acids isolated from an obtained tumor or cancer biopsy sample, or, at the protein level it could e.g. be determined by immunohistochemical co-localization of HPGDS protein and of a TAM-specific protein marker, e.g. CD206 or CD163; or by spatial expression detection techniques). In other words, the HPGDS expression in theTME or TME compartment is then mainly / predominantly / primarily / quantitatively selectivelycontributed by TAMs or occurring in TAMs. The quantification of the “majority” or the“main / predominant / primary / quantitatively selective contribution” of the HPGDS expression willdepend on the tumor or cancer type (and may even differ from patient to patient within the same tumoror cancer type) and / or will depend on the number of cell types in the TME or TME compartmentexpressing HPGDS. In general, the “majority” or the “main / predominant / primary / quantitativelyselective contribution” of the HPGDS expression in the TME or TME compartment can amount to 30% ormore, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or to at least30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80% or at least 90% of the total HPGDSexpression detected or determined in the TME or TME compartment; this major, main, etc. fraction isthus to be contributed or caused by, is originating from, or is occurring in a single cell type, i.e. the TAMs,present in the TME or TME compartment.In one (further) embodiment to the above aspects and embodiments, the inhibitor of HPGDS isselectively inhibiting function or expression (see further) of HPGDS. More in particular, the inhibitor ofHPGDS is a small molecule (e.g. HQL-79, TFC-007, hPGDS inhibitor I, TAS-204, ZL-2102, TAS-205, KMN- MaMa / HPGDS / 822698, SP1, SP2, SP5 and SP10; see hereinabove and in the Examples), a HPGDS degradation inducingproteolysis targeting chimera (HPGDS-targeting PROTAC, see, e.g. Yokoo et al.2021, ACS Med Chem Lett12: 236-241), a DNA nuclease specifically knocking out or disrupting HPGDS, an RNase specificallytargeting HPGDS, or an inhibitory oligonucleotide specifically targeting HPGDS (see further).In one (further) embodiment to the above aspects and embodiments, the inhibitor of HPGDS is combinedwith a further anti-tumor or anti-cancer agent (when already combined with immune checkpointinhibitor (comprising) therapy, the further anti-tumor or anti-cancer agent is different from an immunecheckpoint inhibitor), or is combined with surgery or radiation for purposes of treating a tumor or cancer,inhibiting a tumor or cancer, or inhibiting progression of a tumor or cancer. Functional HPGDSFunctional HPGDS, as referred to herein, is defined as HPGDS that is expressed and to which no “foreign”(in the sense of non-naturally occurring, artificially made, man-made, or any combination thereof)compound such as pharmacological inhibitor is bound or linked, wherein the “foreign” compound iscapable of interfering directly (e.g. competing) or indirectly (e.g. by inducing degradation of HPGDS) withthe binding of HPGDS with any one of its potential natural binding partners. Functional HPGDS may bestored inside (immune) cells.As such, functional HPGDS can be lacking, or be substantially lacking on and / or in a cell by repressing,inhibiting, or blocking expression of HPGDS, or by binding of a “foreign” compound (as meant hereinabove) to HPGDS. In particular, functional HPGDS is lacking, or is substantially lacking, on and / or in an isolated immune cell as described herein (in particular CD8+ T-cells or macrophages). Genetic modification of immune cells isolated from a subject is one means of forcing the immune cellsto (substantially) lack functional HPGDS. Such genetic modification can be aimed at repressing, reducing,or inhibiting ongoing expression of HPGDS in the isolated (unmodified) immune cells, and / or can beaimed at preventing or inhibiting de novo expression of HPGDS, e.g. in case expression of HPGDS is lowor non-existing in the isolated (unmodified) immune cells. In this context, when the isolated immunecells are expanded in vitro or ex vivo, it is understood that the genetic modification may occur prior toexpansion, such as in case of stable genetic modification. When the genetic modification is relying on e.g. RNA interference mechanisms, the isolated immune cells may need to be expanded in the continuous presence of the e.g. RNA interference agent. Shielding (part of the) HPGDS protein exposed on the surface of immune cells and / or stored within immune cells by means of contacting the immune cells with a pharmacological inhibitor of HPGDS isanother means of causing immune cells to (substantially) lack functional HPGDS. The said shielding can MaMa / HPGDS / 822 be envisaged as neutralizing (part of the) HPGDS protein for interaction with other (natural) bindingpartners. In this context, when the isolated immune cells are expanded in vitro or ex vivo, it isunderstood that the contacting with the pharmacological inhibitor is continuous during the expansion of the immune cells, or is occurring after expansion of the immune cells. Such pharmacological inhibitorsper se are known in the art, see above, and alternatives are discussed in more detail hereinafter. Inparticular, such pharmacological inhibitors bind to HPGDS with high specificity and / or, optionally, withhigh affinity.HPGDS protein present inside immune cells or on the surface of immune cells can further be the targetof pharmacologic knock-down such as by molecules or agents inducing specific proteolytic degradationof HPGDS protein. In this context, when the isolated immune cells are expanded in vitro or ex vivo, it isunderstood that the contacting with the pharmacological knock-down agent is continuous during the expansion of the immune cells, or is occurring after expansion of the immune cells.The agent causing an immune cell to (substantially) lack functional HPGDS or causing (substantial)neutralization of HPGDS as referred to herein may be part of a larger molecule further comprising amoiety directing the agent to the immune cell. Immune cells in which HPGDS expression or function is inhibited, and medical usesIn a further aspect, this disclosure relates to isolated macrophages lacking or substantially lackingfunctional HPGDS, to isolated HPGDS knock-out macrophages, or to isolated macrophages conditionallyexpressing an inhibitor of HPGDS, or to populations of any one thereof. Furthermore included arecompositions, such a pharmaceutical compositions, comprising (a population of) isolated macrophages lacking or substantially lacking functional HPGDS, comprising (a population of) isolated HPGDS knock- out macrophages, or comprising (a population of) isolated macrophages conditionally expressing an inhibitor of HPGDS. A further aspect of this disclosure relates to (populations of) isolated macrophages lacking orsubstantially lacking functional HPGDS, to (populations of) isolated HPGDS knock-out macrophages, to(populations of) isolated macrophages conditionally expressing an inhibitor of HPGDS, or topharmaceutical composition comprising any of these, for use as a medicament. More in particular, foruse as a medicament for treating a cancer or tumor, for inhibiting (growth of) a cancer or tumor, or forinhibiting progression of a cancer or tumor or of progression of cancer or tumor growth. Alternatively,the (populations of) isolated macrophages lacking or substantially lacking functional HPGDS, the (populations of) isolated HPGDS knock-out macrophages, (populations of) isolated macrophagesconditionally expressing an inhibitor of HPGDS, or pharmaceutical compositions comprising any of these, MaMa / HPGDS / 822 are for use in the manufacture of a medicament; more in particular, for use in the manufacture of a medicament for treating a cancer or tumor, for inhibiting (growth of) a cancer or tumor, or for inhibitingprogression of a cancer or tumor or of progression of cancer or tumor growth. Further alternatively, thisaspect relates to methods of treating (as subject having) a cancer or tumor, inhibiting (growth of) acancer or tumor (in a subject having a tumor or cancer), or inhibiting progression of a cancer or tumoror of progression of cancer or tumor growth (in a subject having a tumor or cancer), such methods including administering a (population of) isolated macrophages lacking or substantially lacking functional HPGDS, a (population of) isolated HPGDS knock-out macrophages, a (population of) isolated macrophages conditionally expressing an inhibitor of HPGDS, or a pharmaceutical composition comprising any of these, to a subject having a cancer or tumor. In particular, a therapeutically effectiveamount of such (populations of) macrophages or a therapeutically effective amount of suchpharmaceutical composition is administered to the subject. Further in particular, with this administering,the tumor or cancer is treated or inhibited, or its progression is inhibited. In particular to this aspect,such macrophages are for use in a treatment comprising transfer or adoptive transfer of the macrophages to a subject. Adoptive cell transferIn general, adoptive cell transfer (also known as cellular adoptive immunotherapy or cell transfertherapy) refers to the administration of ex-vivo expanded cells, in particular immune cells, to a subjectin need of such adoptive cell transfer, wherein the original (immune) cell is obtained from the subject(in case of autologous cell transfer therapy) prior to its expansion. The ex-vivo expanded (immune) cellscan, prior to their transfer back in the subject, be genetically modified. Well-known genetic modificationsinclude genetic engineering such as to cause the (immune) cells to express antitumor T cell receptors (TCRs) or chimeric antigen receptors (CARs) to increase anti-tumor activity of the transferred (immune) cells. In the context of the present invention, these well-known genetic modifications are not excluded and can be combined with genetic modifications aimed at forcing the macrophage to lack or tosubstantially lack functional HPGDS (as described above). In particular, in view of the experimental datapresented herein, it is plausible that omission of HPGDS in macrophages employed in TCR-engineered orCAR-engineered adoptive cell transfer will further increase their anti-tumor activity. Thus, TCR-engineered macrophages (or TCR-Ms), CAR-engineered macrophages, or CAR-M cells lacking orsubstantially lacking functional HPGDS (as defined hereinabove) are part of the invention.Pharmaceutical compositions comprising TCR-engineered macrophages, CAR-engineered macrophages,or CAR-M or TCR-M cells lacking or substantially lacking functional HPGDS are also part of the invention.It can also be envisaged to take this a step further, i.e., to engineer the cells produced for adoptive cell MaMa / HPGDS / 822transfer to express an inhibitor of HPGDS, or to load expanded cells with an inhibitor of HPGDS prior toadoptive transfer.More in particular, autologous or allogeneic bone marrow derived macrophages can be maintained inculture, optionally in the presence of a HPGDS inhibitor. Such macrophages can be geneticallyengineered or re-directed such as to knock out the HPGDS gene, or by introduction of a vector or othergenetic construct comprising an inducible promotor operably linked to a cassette allowing expression of a genetic or nucleotide based HPGDS-inhibitor (e.g. miRNA, shRNA, antisense RNA, ribozyme). In thelatter case the macrophages are conditionally expressing a HPGDS inhibitor. The engineeredmacrophages can subsequently be transferred into a subject, such as to treat a cancer or tumor asdescribed hereinabove. In case of macrophages engineered towards inducible HPGDS-inhibition, the expression inducing compound is administered at an appropriate timepoint to the subject having received the engineered macrophages. The transfer (adoptive cell transfer) can be autologous or heterologous. Adoptive macrophage transfer has been described in the literature (e.g. Ma et al.2015, Brain Behaviour Immunity 45:157-170; Parsa et al. 2012, Diabetes 61:2881-2892; Wang et al. 2007,Kidney Int 72:290-299; Zhang et al.2014, Glia 62:804-817). In addition, such modified macrophages cancarry a further modification so that they can function as e.g. chimeric antigen receptor macrophages(CAR-M, e.g. Wang et al. 2022, eBioMedicine 76:103873) or T cell receptor (TCR-M). Or, vice versa,isolated CAR-Ms or TCR-Ms may be HPGDS knock-out CAR-Ms or TCR-Ms, or isolated CAR-Ms or TCR-Ms conditionally expressing an inhibitor of HPGDS. Such CAR-Ms or TCR-Ms likewise find use as amedicament; are for use in the manufacture of a medicament; or find application in methods of treatinga disease or disorder in a subject, comprising administering (an effective dose of) the CAR-Ms or TCR-Msto a subject in need of being treated. More in particular, the disease or disorder is not limited to canceror a tumor, as the nature of the CAR- or TCR- ligand may be determining the targeted disease or disorderand the inhibition of HPGDS may be additionally beneficial in directing the CAR-Ms or TCR-Ms to the M1phenotype. In this context, this disclosure therefore also relates to methods of producing autologous orallogeneic M1-type macrophages, such as M1-type CAR-M or M1-type TCR-M, comprising inhibitingexpression of HPGDS in macrophages obtained from a subject or in macrophages differentiated ex-vivofrom monocytes obtained from a subject.Combination with immune checkpoint inhibitorIn yet a further aspect, this disclosure relates to combinations of an immune checkpoint inhibitor on theone hand and of an inhibitor of HPGDS, a (population of) isolated macrophages (or CAR-Ms or TCR-M)slacking or substantially lacking functional HPGDS, a (population of) isolated HPGDS knock-out MaMa / HPGDS / 822macrophages (or CAR-Ms or TCR-Ms), and / or a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS on the other hand. More in particular, suchcombinations are for use as a medicament or for use in the manufacture of a medicament. Themedicament is in one embodiment a medicament for treating a cancer or tumor, for inhibiting (growthof) a cancer or tumor, or for inhibiting progression of a cancer or tumor or of progression of cancer ortumor growth. Alternatively, this aspect relates to methods of for treating a (subject having a) cancer ortumor, for inhibiting (growth of ) a cancer or tumor (in a subject having a tumor or cancer), or forinhibiting progression of a cancer or tumor or of progression of cancer or tumor growth (in a subjecthaving a tumor or cancer), such methods comprising administering a (therapeutically effective amountof a) combination of an immune checkpoint inhibitor and of an inhibitor of HPGDS, a (population of)isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, a(population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), and / or a (population of)isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS to a subjecthaving the cancer or tumor. Such administering in particular results in treating the cancer or tumor, ininhibiting (growth of) the cancer or tumor, or in inhibiting progression of the cancer or tumor or ofprogression of cancer or tumor growth. Furthermore in particular, the said macrophage is a CAR-M orTCR-M. The combination may be in any possible way as will be described in more detail hereinafter.Diagnostic methodsIn further aspects, this disclosure relates to diagnostic-type methods or companion diagnostic-typemethods.One such aspect includes methods of or for selecting, or determining the eligibility of, a subject havingcancer for therapy including / with an inhibitor of HPGDS, or for therapy including / with a (population of)isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, fortherapy including / with (a population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or for therapy including / with (a population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS or of predicting the response, the likelihood of response, or responsiveness of a subject having cancerto therapy including / with an inhibitor of HPGDS, to therapy including / with a (population of) isolatedmacrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, to therapyincluding / with (a population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or totherapy including / with (a population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionallyexpressing an inhibitor of HPGDS, such methods comprising: MaMa / HPGDS / 822 measuring, determining, assessing, quantifying, or analyzing the expression of HPGDS in a tumor biopsy sample obtained from the subject, and selecting a subject having cancer or determining a subject havingcancer to be eligible for therapy including / with an inhibitor, for therapy including / with a (population of)isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, fortherapy including / with (a population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or for therapy including / with (a population of) isolated macrophages (or CAR-Ms or TCR-Ms)conditionally expressing an inhibitor of HPGDS:when the HPGDS expression in the tumor biopsy sample is limited to expression in tumor- or cancer-associated macrophages in the tumor micro-environment (TME) or TME compartment, or when HPGDSis selectively expressed in tumor- or cancer-associated macrophages compared to in other cells in theTME or TME compartment; or when the tumor or cancer micro-environment or TME compartment of the tumor or cancer ischaracterized in that the total amount of expression of HPGDS in the TME or TME compartment ismainly / predominantly / primarily / quantitatively selectively contributed by or occurring in tumor- orcancer-associated macrophages; orwhen the tumor- or cancer-associated macrophages in the TME or TME compartmentare themain / predominant / primary / quantitatively selective contributors to the total amount of expression of HPGDS in the TME or TME compartmentof the tumor or cancer.In one embodiment, the tumor biopsy sample is obtained prior to starting therapy with a HPGDSinhibitor, i.e. the tumor biopsy sample is a pre-therapy tumor biopsy sample, or is a pre-HPGDS inhibitor therapy tumor biopsy sample.Another such diagnostic-type aspect includes methods of or for selecting or determining the eligibilityof a subject having a cancer poorly responding or non-responsive to immune checkpoint inhibitortherapy for treatment including / with an inhibitor of HPGDS, for treatment including / with a (populationof) isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, fortreatment including / with (a population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or for treatment including / with (a population of) isolated macrophages (or CAR-Ms or TCR-Ms)conditionally expressing an inhibitor of HPGDS, comprising: measuring, determining, assessing,quantifying, or analyzing the expression of HPGDS in a tumor biopsy sample obtained from the subject,and selecting a subject or determining a subject to be eligible for treatment including / with an inhibitorof HPGDS, for treatment including / with a (population of) isolated macrophages (or CAR-Ms or TCR-Ms)lacking or substantially lacking functional HPGDS, for treatment including / with (a population of) isolated MaMa / HPGDS / 822HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or for treatment including / with (a populationof) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS:when the HPGDS expression in the tumor biopsy sample is limited to expression in tumor- or cancer-associated macrophages in the TME or TME compartment, or when HPGDS is selectively expressed intumor- or cancer-associated macrophages compared to in other cells in the TME or TME compartment;or when the TME or TME compartmentof the tumor or cancer is characterized in that the total amount ofexpression of HPGDS in the TME or TME compartment is mainly / predominantly / primarily / quantitativelyselectively contributed by or occurring in tumor- or cancer-associated macrophages; orwhen the tumor- or cancer-associated macrophages in the TME or TME compartmentare themain / predominant / primary / quantitatively selective contributors to the total amount of expression of HPGDS in the TME or TME compartmentof the tumor or cancer.In one embodiment, the tumor biopsy sample is obtained after start of the therapy including / with animmune checkpoint inhibitor, i.e. the tumor biopsy sample is an on-therapy tumor biopsy sample, or isan on- immune checkpoint inhibitor therapy tumor biopsy sample. In a further embodiment, the HPGDSexpression level (in the TAMs) is high, or is corresponding to reference HPGDS expression levels that areindicative of poor response or non-response of a subject having the cancer to the therapy including anICI or to the therapy with an ICI. In a further embodiment, the treatment with an inhibitor of HPGDS isan additional treatment, i.e. additional to treatment or therapy with an immune checkpoint inhibitor, oradditional to treatment or therapy including an immune checkpoint inhibitor. In a further embodiment,the expression of programmed death 1 (PD1) in the tumor biopsy sample is measured, determined,assessed, quantified, or analyzed. A further diagnostic-type aspect includes methods of or for determining early response of subject having cancer to immune checkpoint inhibitor therapy or to therapy including an immune checkpoint inhibitor,comprising: measuring, determining, assessing, quantifying, or analyzing the expression of HPGDS in apre- and on-treatment / therapy tumor biopsy sample obtained from the subject, and determining thesubject to respond to immune checkpoint inhibitor therapy or to therapy including an immunecheckpoint inhibitor when HPGDS expression in the on-treatment / therapy tumor biopsy sample is loweror significantly lower compared to the HPGDS expression in the pre-treatment / therapy tumor biopsysample. More in particular, the pre- and on-treatment / therapy tumor biopsy samples refer to samplesobtained prior to start of and after start of, respectively, treatment or therapy with or including animmune checkpoint inhibitor. In one embodiment, the on-treatment / therapy tumor biopsy sample is asample obtained early on-treatment / therapy (early on-treatment / therapy tumor biopsy sample), such MaMa / HPGDS / 822 as obtained after one cycle of treatment or therapy with or including an immune checkpoint inhibitor. In a further embodiment, the expression of programmed death 1 (PD1) in the tumor biopsy sample is measured, determined, assessed, quantified, or analyzed.Alternatively, such methods of or for determining early response of subject having cancer to immunecheckpoint inhibitor therapy or to therapy including an immune checkpoint inhibitor (ICI), arecomprising: measuring, determining, assessing, quantifying, or analyzing the expression of HPGDS in anon-treatment / therapy tumor biopsy sample obtained from the subject, and determining the subject torespond to immune checkpoint inhibitor therapy or to therapy including an immune checkpoint inhibitorwhen the level of HPGDS expression in the on-treatment / therapy tumor biopsy sample corresponds toreference on-treatment / therapy tumor biopsy sample HPGDS expression levels that are indicative of response of a subject having the cancer to the treatment / therapy including an ICI or to the therapy withan ICI; or alternatively determining the subject not to respond to immune checkpoint inhibitor therapyor to therapy including an immune checkpoint inhibitor when the level of HPGDS expression in the on-treatment / therapy tumor biopsy sample corresponds to reference on-treatment / therapy tumor biopsysample HPGDS expression levels that are indicative of non-response of a subject having the cancer tothe treatment / therapy including an ICI or to the therapy with an ICI. In one embodiment, the on-treatment / therapy tumor biopsy sample is a sample obtained early on-treatment / therapy (early on-treatment / therapy tumor biopsy sample), such as obtained after one cycle of treatment or therapy withor including an immune checkpoint inhibitor. In a further embodiment, the expression of programmed death 1 (PD1) in the tumor biopsy sample is measured, determined, assessed, quantified, or analyzed.Medical use combined with diagnostic methodsThis disclosure further relates to either:an inhibitor of hematopoietic prostaglandin D synthase (HPGDS) for use in treating a tumor or cancer,inhibiting (growth of) a tumor or cancer, or inhibiting progression of a tumor or cancer or of progressionof tumor or cancer growth; oran inhibitor of hematopoietic prostaglandin D synthase (HPGDS) for use in the manufacture of amedicament for treating a tumor or cancer, for inhibiting (growth of) a tumor or cancer, or for inhibitingprogression of a tumor or cancer or of progression of tumor or cancer growth; ora method of treating a (subject having) a tumor or cancer, of inhibiting (growth of) a tumor or cancer, orof inhibiting progression of a tumor or cancer or of progression of tumor or cancer growth, such methodsincluding administering a (therapeutically effective dose of a) HPGDS inhibitor to the subject having atumor or cancer; or MaMa / HPGDS / 822 an inhibitor of HPGDS for use in potentiating treatment with or including an immune checkpoint inhibitor therapy of a tumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy; or a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functionalHPGDS, a (population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), a (populationof) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS, or apharmaceutical composition comprising any of these, for use in treating a tumor or cancer, inhibiting(growth of) a tumor or cancer, or inhibiting progression of a tumor or cancer or of progression of tumoror cancer growth; ora (population of) isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functionalHPGDS, a (population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), a (populationof) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS, or apharmaceutical composition comprising any of these, for use in the manufacture of a medicament for treating a tumor or cancer, inhibiting (growth of) a tumor or cancer, or inhibiting progression of a tumoror cancer or of progression of tumor or cancer growth; ora method of treating a (subject having) a tumor or cancer, of inhibiting (growth of) a tumor or cancer, orof inhibiting progression of a tumor or cancer or of progression of tumor or cancer growth, such methodsincluding administering a (therapeutically effective dose of a (population of) isolated macrophages (orCAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, of a (population of) isolated HPGDSknock-out macrophages (or CAR-Ms or TCR-Ms), of a (population of) isolated macrophages (or CAR-Msor TCR-Ms) conditionally expressing an inhibitor of HPGDS, or a pharmaceutical composition comprisingany one of these, to the subject having a tumor or cancer;either of these comprising or further comprising selecting or determining the eligibility of a subjecthaving cancer for therapy including / with an inhibitor of HPGDS, including / with a (population of) isolatedmacrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, including / with (apopulation of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or including / with (apopulation of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor ofHPGDS according to the appropriate above-described methods.This disclosure further relates to either: an inhibitor of HPGDS, including / with a (population of) isolated macrophages (or CAR-Ms or TCR-Ms)lacking or substantially lacking functional HPGDS, including / with (a population of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or including / with (a population of) isolated macrophages (orCAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS for use in the manufacture of a MaMa / HPGDS / 822 medicament for use in potentiating treatment with or including an immune checkpoint inhibitor therapy of a tumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy; or a method of treating a (subject having a) tumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy (or therapy comprising an immune checkpoint inhibitor), such methods including potentiating treatment with or including an immune checkpoint inhibitor (comprising) therapy of a tumor or cancer by administering (a therapeutically effective dose of) aninhibitor of HPGDS, (a therapeutically effective dose of) a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, (a therapeutically effective dose of) (apopulation of) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or (a therapeuticallyeffective dose of) (a population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionallyexpressing an inhibitor of HPGDS to the subject having a tumor or cancer;either of these comprising or further comprising selecting or determining the eligibility of a subjecthaving a cancer poorly responding or non-responsive to immune checkpoint inhibitor therapy fortreatment including / with an inhibitor of HPGDS, including / with a (population of) isolated macrophages(or CAR-Ms or TCR-Ms) lacking or substantially lacking functional HPGDS, including / with (a populationof) isolated HPGDS knock-out macrophages (or CAR-Ms or TCR-Ms), or with (a population of) isolatedmacrophages (or CAR-Ms or TCR-Ms) conditionally expressing an inhibitor of HPGDS according to theappropriate above-described methods.Diagnostic KitsThis disclosure further relates to (diagnostic) kits comprising one or more containers or vials (any suitablecontainer or vial, such as a pharmaceutically acceptable container or vial) comprising a (labelled)antibody or (labelled) oligonucleotide to detect an Hpgds gene expression product. In particular the(labelled) antibody or (labelled) oligonucleotide is in one embodiment adapted for multiplex in situanalysis or detection (see sections on spatial proteomics / transcriptomics). Further (labeled) antibodiesor (labeled) oligonucleotides can be comprised in these kits, e.g. targeting a TAM-specific gene or gene product, e.g. CD206 or CD163. Further in particular, the kit is a kit for use or can be used in performing the above-described methodsof selecting eligibility of a subject having a tumor or cancer to be treated with an inhibitor of HPGDS, anisolated HPGDS knock-out macrophage, or an isolated macrophage conditionally expressing an inhibitorof HPGDS; or for selecting eligibility of a subject having a cancer poorly responding or non-responsive toimmune checkpoint inhibitor therapy for (additional) therapy including or with an inhibitor of HPGDS orfor (additional) therapy with an isolated HPGDS knock-out macrophage, or an isolated macrophage MaMa / HPGDS / 822 conditionally expressing an inhibitor of HPGDS; or for use in performing the above-described methodsof or for determining response of subject having cancer to immune checkpoint inhibitor therapy or totherapy including an immune checkpoint inhibitor. Other optional components of such kit include one or more (further) diagnostic agents capable of predicting, prognosing, or determining the success of a therapy comprising one of the therapiesaccording to the current disclosure; use instructions; one or more containers with sterilepharmaceutically acceptable carriers, excipients or diluents; one or more syringes; one or more needles;etc. In particular, such kits may be diagnostic kits or companion diagnostic kits.Therapeutic or pharmaceutical kitsThis disclosure further relates to (therapeutic / pharmaceutical / medicament) kits comprising a containeror vial (any suitable container or vial, such as a pharmaceutically acceptable container or vial) comprising an inhibitor of HPGDS, a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) lacking orsubstantially lacking functional HPGDS, a (population of) isolated HPGDS knock-out macrophages (orCAR-Ms or TCR-Ms), or a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionallyexpressing an inhibitor of HPGDS as described hereinabove, or comprising a composition comprising aninhibitor of HPGDS, a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) lacking orsubstantially lacking functional HPGDS, a (population of) isolated HPGDS knock-out macrophages (orCAR-Ms or TCR-Ms), or a (population of) isolated macrophages (or CAR-Ms or TCR-Ms) conditionallyexpressing an inhibitor of HPGDS as described hereinabove. Other optional components of such kitsinclude e.g. a container or vial (any suitable container or vial, such as a pharmaceutically acceptablecontainer or vial) comprising a further anti-tumor or anti-cancer agent (such as e.g. an immunecheckpoint inhibitor). Further optional components of such kit include use instructions (e.g. the kit insertapproved by a regulatory instance such as FDA or EMEA); one or more containers with sterilepharmaceutically acceptable carriers, excipients or diluents [such as for producing or formulating a(pharmaceutically acceptable) composition of the current disclosure]; one or more syringes; one or moreneedles; etc. In particular, such kits may be pharmaceutical kits. Reference, standard or control / reference, standard or control expression levelStandards or controls for the expression level, or a reference, standard or control expression level (attranscriptomic level or at proteomic level) of a biomarker gene as listed above (including HPGDSexpression and PD1 expression) can be defined in some alternative ways.In one embodiment, such reference, standard or control expression level refers to a pre-determined range of expression levels / standard values. Typically such ranges are defined after collecting a set of MaMa / HPGDS / 822expression levels of a gene of interest as determined in a suitable number of cancer patients. As outlinedin the Examples herein, the expression of the HPGDS gene is lower in responders to therapy comprisingan immune checkpoint inhibitor (ICI) or to therapy with an ICI versus / compared to in non-responders tosuch therapy. From these, suitable reference, standard, or control HPGDS expression levels or HPGDSexpression level ranges reflecting response to therapy with or comprising an ICI can be determined ordefined. Vice versa, suitable reference, standard, or control HPGDS expression levels or HPGDSexpression level ranges reflecting non-response to therapy with or comprising an ICI can be determinedor defined – these will be higher than reference, standard, or control HPGDS expression levels or levelranges defined for the responders to therapy with or comprising an ICI. Ideally, reference HPGDSexpression levels or level ranges defined for responders do not overlap with reference HPGDS expression levels or level ranges defined for non-responders.The HPGDS expression level as determined in any of the above methods for selecting a cancer patient tobe potentially eligible for treatment with a therapy comprising an immune checkpoint inhibitor (ICI) or to a therapy with an ICI (the test subject) can alternatively be compared with the HPGDS expression levelat a similar time-point in a cancer patient or set of cancer patients known as (subsequent) responder(s)(or non-responder(s)) to the therapy comprising an immune checkpoint inhibitor (ICI) or to the therapywith an ICI (the control subject(s)). If the HPGDS expression level in the test subject is (roughly / about)equal to the HPGDS expression level in a responding control subject, or is lower than the HPGDSexpression level in a non-responding control subject, then the test subject is predicted to be a responder to the therapy including / with an ICI. If the HPGDS expression level in the test subject is (roughly / about)equal to the HPGDS expression level in a non-responding control subject, or is higher than the HPGDSexpression level in a non-responding control subject, then the test subject is predicted to be a non- responder to the therapy including / with an ICI.In particular, the expression level of a gene of interest is determined by normalization relative toexpression of e.g. a housekeeping gene or set of housekeeping genes. Any method, diagnostic kit ordevice designed to operate according to any of the above-listed methods of the current disclosure (seefurther) therefore may include the option / possibility to determine, assess, measure, quantify expressionof one or more household genes in addition to the means to determine, assess, measure, quantifyexpression of a gene of interest predictive for outcome of therapy comprising an immune checkpointinhibitor (ICI) or of therapy with an ICI in a subject having cancer, or predictive for (early) response orpredictive for (early) response of a subject having cancer to therapy comprising an immune checkpoint inhibitor (ICI) or to therapy with an ICI.The higher HPGDS gene expression level in non-responders to therapy comprising an immune checkpointinhibitor (ICI) or to therapy with an ICI versus / compared to in responders to therapy comprising an MaMa / HPGDS / 822immune checkpoint inhibitor (ICI) or to therapy with an ICI can be higher with 5% or more, 10% or more,15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% ormore, 90% or more, 95% or more, 100% or more; or with up to 10%, up to 20%, of up to 30%, of up to40%, of up to 50%, of up to 60%, of up to 70%, of up to 80%, of up to 90%, or with up to 100% or more.In case of a 100% higher analyte strand number of the biomarker gene, the expression of the biomarkerhas doubled, or increased 2-fold. The higher analyte strand number of the biomarker can further be 1.1-fold higher, 1.2-fold higher, 1.3-fold higher, 1.4-fold higher, 1.5-fold higher, 1.6-fold higher, 1.7-fold higher, 1.8-fold higher, 1.9-fold higher, 2-fold higher, 2.1-fold higher, 2.2-fold higher, 2.3-fold higher, 2.4-fold higher, 2.5-fold higher, 2.6-fold higher, 2.7-fold higher, 2.8-fold higher, 2.9-fold higher, 3-foldhigher, more than 3-fold higher, 3.5-fold higher, 4-fold higher, more than 4-fold higher, between 3-foldand 4-fold higher, 4.5-fold higher, 5-fold higher, more than 5-fold higher, between 2-fold and 5-foldhigher, between 3-fold and 5-fold higher, between3-fold and 5-fold higher, 6-fold higher, more than 6-fold higher, between 2-fold and 6-fold higher, between 3-fold and 6-fold higher, between 4-fold and 6-fold higher, 7-fold higher, more than 7-fold higher, 8-fold higher, lore than 8-fold higher, 9-fold higher,more than 9-fold higher, 10-fold higher, up to 10-fold higher, more than 10-fold higher, between 2-foldand 10-fold higher, between 3-fold and 10-fold higher, between 4-fold and 10-fold higher, between 5-fold and 10-fold higher, between 6-fold and 10-fold higher, between 7-fold and 10-fold higher, between8-fold and 10-fold higher, substantially more than 10-fold higher, between 10-fold and 15-fold higher,up to 15-fold higher, between 10-fold and 20-fold higher, up to 20-fold higher, substantially more than20-fold in higher crease such as up to 25-fold higher, up to 30-fold higher, up to 40-fold higher, or up to50-fold higher. Inhibition of a target of interest The term “antagonist” or “inhibitor” of a target as used interchangeable herein refers to inhibitors of function or to inhibitors of expression of a target of interest. Interchangeable alternatives for “antagonist” include inhibitor, repressor, suppressor, inactivator, and blocker. An “antagonist” thus refers to a molecule that decreases, blocks, inhibits, abrogates, or interferes with target expression, activation, function, or activity. Downregulating of expression of a gene encoding a target is feasible through antagonists including entities such as antisense oligonucleotides, gapmers, siRNA, shRNA, zinc-finger nucleases, meganucleases, TAL effector nucleases, CRISPR-Cas effectors, etc. (general description of these compounds included hereinafter). MaMa / HPGDS / 822Inactivation or inhibition of a process as envisaged in the current disclosure refers to different possiblelevels of inactivation or inhibition, e.g., at least 10%, at least 20%, at least 30%, at least 40%, at least50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even 100% or more ifinactivation or inhibition (compared to a normal situation or compared to the situation prior to startingthe inactivation or inhibition). The nature of the inactivating / inhibitory compound is not vital / essentialto the invention as long as the process envisaged is inactivated / inhibited such as to treat or inhibit(progression of) the disease or disorder as described herein. Selectively downregulating expression of a gene encoding a target is feasible through agents includeentities such as antisense oligonucleotides, gapmers, siRNA, shRNA, zinc-finger nucleases,meganucleases, Argonaute, TAL effector nucleases, CRISPR-Cas effectors, and nucleic acid aptamers. In particular, any of these agents is specifically, selectively, or exclusively acting on or antagonizing the target of interest; or any of these agents is designed for specifically, selectively, or exclusively acting onor antagonizing the target of interest. In the context of the present disclosure, the target of interest inparticular is HPGDS. One process of selectively modulating / downregulating expression of a gene / target gene of interest relies on antisense oligonucleotides (ASOs), or variants thereof such as gapmers. An antisense oligonucleotide (ASO) is a short strand of nucleotides and / or nucleotide analogues that hybridizes with the complementary mRNA in a sequence-specific or -selective manner. Formation of the ASO–mRNA complex ultimately results in downregulation of target protein expression (Chan et al. 2006, Clin Exp Pharmacol Physiol 33:533-540; this reference also describes some of the software available for assisting in design of ASOs). Modifications to ASOs can be introduced at one or more levels: phosphate linkage modification (e.g. introduction of one or more of phosphodiester, phosphoramidate or phosphorothioate bonds), sugar modification (e.g. introduction of one or more of LNA (locked nucleic acids), 2ʹ-O-methyl, 2ʹ-O-methoxy-ethyl, 2’-fluoro, S-constrained ethyl or tricyclo-DNA and / or non-ribose modifications (e.g. introduction of one or more of phosphorodiamidate morpholinos or peptide nucleic acids). The introduction of 2ʹ-modifications has been shown to enhance safety and pharmacologic properties of antisense oligonucleotides. Antisense strategies relying on degradation of mRNA by RNase H requires the presence of nucleotides with a free 2’-oxygen, i.e. not all nucleotides in the antisense molecule should be 2’-modified. The gapmer strategy has been developed to this end. A gapmer antisense oligonucleotide consists of a central DNA region (usually a minimum of 7 or 8 nucleotides) with (usually 2 or 3) 2ʹ-modified nucleosides flanking both ends of the central DNA region. This is sufficient for the protection against exonucleases while allowing RNAseH to act on the (2’-modification free) gap region. Antidote strategies are available as demonstrated by administration of an oligonucleotide fully MaMa / HPGDS / 822 complementary to the antisense oligonucleotide (Crosby et al. 2015, Nucleic Acid Ther 25:297-305). Uptake of oligonucleotides by cells can be spontaneous or be assisted by e.g. transfection etc.. Another process to selectively modulate expression of a gene / target gene of interest is based on the natural process of RNA interference. It relies on double-stranded RNA (dsRNA) that is cut by an enzymecalled Dicer, resulting in double stranded small interfering RNA (siRNA) molecules which are 20-25nucleotides long. siRNA then binds to the cellular RNA-Induced Silencing Complex (RISC) separating the two strands into the passenger and guide strand. While the passenger strand is degraded, RISC is cleaving mRNA specifically or selectively at a site instructed by the guide strand. Destruction of the mRNA prevents production of the protein of interest and the gene is ‘silenced’. siRNAs are dsRNAs with 2 nt 3’ end overhangs whereas shRNAs are dsRNAs that contains a loop structure that is processed to siRNA. shRNAs are introduced into the nuclei of target cells using a vector (e.g. bacterial or viral) that optionally can stably integrate into the genome. Apart from checking for lack of cross-reactivity with non-target genes, manufacturers of RNAi products provide guidelines for designing siRNA / shRNA. siRNA sequences between 19–29 nt are generally the most effective. Sequences longer than 30 nt can result in nonspecific silencing. Ideal sites to target include AA dinucleotides and the 19 nt 3’ of them in the target mRNA sequence. Typically, siRNAs with 3’ dUdU or dTdT dinucleotide overhangs are more effective. Other dinucleotide overhangs could maintain activity but GG overhangs should be avoided. Also to be avoided are siRNA designs with a 4–6 poly(T) tract (acting as a termination signal for RNA pol III), and the G / C content is advised to be between 35–55%. shRNAs should comprise sense and antisense sequences (advised to each be 19–21 nt in length) separated by loop structure, and a 3’ AAAA overhang. Effective loop structures are suggested to be 3-9 nt in length. It is suggested to follow the sense-loop-antisense order in designing the shRNA cassette and to avoid 5’ overhangs in the shRNA construct. shRNAs areusually transcribed from vectors, e.g. driven by the Pol III U6 promoter or H1 promoter. Vectors allowfor inducible shRNA expression, e.g. relying on the Tet-on and Tet-off inducible systems commercially available, or on a modified U6 promoter that is induced by the insect hormone ecdysone. A Cre-Lox recombination system has been used to achieve controlled expression in mice. Synthetic shRNAs can be chemically modified to affect their activity and stability. Plasmid DNA or dsRNA can be delivered to a cell by means of transfection (lipid transfection, cationic polymer-based nanoparticles, lipid or cell- penetrating peptide conjugation) or electroporation. Vectors include viral vectors such as lentiviral, retroviral, adenoviral and adeno-associated viral vectors. Ribozymes (ribonucleic acid enzymes) are another type of molecules that can be used to selectively modulate expression of a gene / target gene of interest. They are RNA molecules capable of catalyzing specific biochemical reactions, in the current context capable of targeted cleavage of nucleotide MaMa / HPGDS / 822 sequences, in particular targeted cleavage of a RNA / RNA target of interest. Examples of ribozymes include the hammerhead ribozyme, the Varkud Satellite ribozyme, Leadzyme and the hairpin ribozyme. Besides the use of the inhibitory RNA technology, modulation of expression of a gene of interest can be achieved at DNA level such as by gene therapy to knock-out, knock-down or disrupt the target gene / gene of interest. As used herein, a “gene knock-out” can be a gene knockdown or the gene can be knocked out, knocked down, disrupted or modified by a mutation such as, a point mutation, an insertion, a deletion, a frameshift, or a missense mutation by techniques such as described hereafter, including, but not limited to, retroviral gene transfer. One way in which genes can be knocked out, knocked down, disrupted or modified is by the use of zinc finger nucleases. Zinc-finger nucleases (ZFNs) are artificial restriction enzymes generated by fusing a zinc finger DNA-binding domain to a DNA-cleavage domain. Zinc finger domains can be engineered to target a desired DNA sequence / DNA sequence of interest, which enable zinc-finger nucleases to target unique sequence within a complex genome. By taking advantage of the endogenous DNA repair machinery, these reagents can be used to precisely alter the genomes of higher organisms. Other technologies for genome customization that can be used to specifically or selectively knock out, knock down or disrupt a gene / gene of interest are meganucleases and TAL effector nucleases (TALENs, Cellectis bioresearch). A TALEN® is composed of a TALE DNA binding domain for sequence-specific or sequence-selective recognition fused to the catalytic domain of an endonuclease that introduces double strand breaks (DSB). The DNA binding domain of a TALEN® is capable of targeting with high precision a large recognition site (for instance 17bp). Meganucleases are sequence-specific or sequence-selective endonucleases, naturally occurring “DNA scissors”, originating from a variety of single-celled organisms such as bacteria, yeast, algae and some plant organelles. Meganucleases have long recognition sites of between 12 and 30 base pairs. The recognition site of natural meganucleases can be modified in order to target native genomic DNA sequences (such as endogenous genes) or DNA sequences of interest. Another recent genome editing technology is the CRISPR / Cas system, which can be used to achieve RNA- guided genome engineering (including knock-out, knock-down or disruption of a gene of interest). CRISPR interference is a genetic technique which allows for sequence-specific or sequence-selective control of expression of a gene of interest in prokaryotic and eukaryotic cells. It is based on the bacterial immune system-derived CRISPR (clustered regularly interspaced palindromic repeats) pathway. Recently, it was demonstrated that the CRISPR-Cas editing system can also be used to target RNA. It has been shown that the Class 2 type VI-A CRISPR-Cas effector C2c2 (Cas13a; CRISPR-Cas13a or CRISPR-C2c2) can be programmed to cleave single stranded RNA targets carrying complementary protospacers (Abudayyeh et al. 2016 Science353 / science.aaf5573). C2c2 is a single-effector endoRNase mediating ssRNA cleavage once it has been guided by a single crRNA guide toward a target RNA / RNA of interest. MaMa / HPGDS / 822 Methods for administering nucleic acid-based therapeutic modalities / agents include methods applying non-viral (DNA or RNA) or viral nucleic acids (DNA or RNA viral vectors). Methods for non-viral nucleicacid administration include the injection of naked DNA (circular or linear), electroporation, the gene gun,sonoporation, magnetofection, the use of oligonucleotides, lipoplexes (e.g. complexes of nucleic acid with DOTAP or DOPE or combinations thereof, complexes with other cationic lipids), dendrimers, viral- like particles, inorganic nanoparticles, hydrodynamic delivery, photochemical internalization (Berg et al. 2010, Methods Mol Biol 635:133-145) or combinations thereof.Many different vectors have been used in nucleic acid administration. Currently the major groups areadenovirus or adeno-associated virus vectors, retrovirus vectors , naked or plasmid DNA, and lentivirus vectors. Combinations are also possible, e.g. naked or plasmid DNA combined with adenovirus, or RNA combined with naked or plasmid DNA to list just a few. Other viruses (e.g. alphaviruses, vaccinia virusessuch as vaccinia virus Ankara) are used in nucleic acid administration and are not excluded in the contextof the current disclosure. Administration may be aided by specific formulation of the nucleic acid e.g. in liposomes (lipoplexes) or polymersomes (synthetic variants of liposomes), as polyplexes (nucleic acid complexed with polymers), carried on dendrimers, in inorganic (nano)particles (e.g. containing iron oxide in case of magnetofection),or combined with a cell penetrating peptide (CPP) to increase cellular uptake. Organ- or cellular-targetingstrategies may also be applied to the nucleic acid (nucleic acid combined with organ- or cell-targetingmoiety); these include passive targeting (mostly achieved by adapted formulation) or active targeting (e.g. by coupling a nucleic acid-comprising nanoparticle with any compound (e.g. an aptamer or antibodyor antigen binding molecule) binding to a target organ- or cell-specific antigen) (e.g. Steichen et al.2013,Eur J Pharm Sci 48:416-427). CPPs enable translocation of their payload of interest across the plasma membrane. CPPs are alternatively termed Protein Transduction Domains (TPDs), usually comprise 30 or less (e.g.5 to 30, or 5 to 20) amino acids, and usually are rich in basic residues, and are derived from naturally occurring CPPs (usually longer than 20 amino acids), or are the result of modelling or design. A non-limiting selection of CPPs includes the TAT peptide (derived from HIV-1 Tat protein), penetratin (derived from DrosophilaAntennapedia – Antp), pVEC (derived from murine vascular endothelial cadherin), signal-sequence basedpeptides or membrane translocating sequences, model amphipathic peptide (MAP), transportan, MPG, polyarginines; more information on these peptides can be found in Torchilin 2008 (Adv Drug Deliv Rev 60:548-558) and references cited therein. CPPs can be coupled to carriers such as nanoparticles, liposomes, micelles, or generally any hydrophobic particle. Coupling can be by absorption or chemical bonding, such as via a spacer between the CPP and the carrier. To increase target specificity or target selectivity, an antibody binding to a target-specific antigen can further be coupled to the carrier MaMa / HPGDS / 822 (Torchilin 2008, Adv Drug Deliv Rev 60:548-558). CPPs have already been used to deliver payloads as diverse as plasmid DNA, oligonucleotides, siRNA, peptide nucleic acids (PNA), proteins and peptides, small molecules and nanoparticles inside the cell (Stalmans et al.2013, PloS One 8:e71752). Any other modification of the DNA or RNA to enhance efficacy of nucleic acid therapy is likewise envisaged to be useful in the context of the applications as outlined herein. The enhanced efficacy can reside in enhanced expression, enhanced delivery properties, enhanced stability and the like. A specific or selective inhibitor of a target of interest may exert the desired level of inhibition of the target of interest with an IC50 of 1000 nM or less, with an IC50 of 500 nM or less, with an IC50 of 100 nM or less, with an IC50 of 50 nM or less, with an IC50 of 10 nM or less, with an IC50 of 1 nM or less, with an IC50 between 1 pM and 1nM, or with an IC50 between 0.1 pM and 10 nM. Cross-inhibition of more than one target is possible; for clinical development it can e.g. be desired to be able to test an inhibitor in a suitable in vitro model or in vivo animal model before starting clinical testing with the same inhibitor in a human population, which may require the inhibitor to cross-inhibit the animal (or other non-human) target and the orthologous human target. Specificity or selectivity of inhibition refers to the situation in which an inhibitor is, at a certainconcentration (sufficient to inhibit the target of interest) inhibiting the target gene or protein with higherefficacy (e.g. with an at least 2-fold, 5-fold, or 10-fold lower IC50, e.g. at least 20-, 50- or 100-fold ormore lower IC50) than the efficacy with which it is possibly (if at all) inhibiting other targets (targets not of interest). Such specificity or selectivity of inhibition is in particular determined within the setting of the target subject (e.g. human patient, or animal model) and thus can encompass / does not exclude inhibition of (at least one) orthologous target. Exclusivity of inhibition refers to the situation in which an inhibitor is inhibiting only the target of interest. Specificity or selectivity of cell targeting, in particular macrophage / tumor-associated macrophage (TAM) / CAR-M targeting refers to the situation in which a composition, at a certain concentration, is interacting with the intended target cell (such as binding to, or such as causing inhibition of function orexpression of HPGDS in the intended target cell) with higher efficacy (e.g. with an at least 2-fold, 5-fold,or 10-fold higher efficacy, or e.g. with at least 20-, 50- or 100-fold higher efficacy) than the efficacy withwhich the composition is interacting with other cells (not intended as target cell). Exclusivity of celltargeting refers to the situation in which a composition is interacting only with the intended target cell.Treatment / therapeutically effective amount The terms therapeutic modality, therapeutic agent, agent, and drug are used interchangeably herein,and likewise relate to the macrophages as described herein (with inhibited function or expression of MaMa / HPGDS / 822 HPGDS). All refer to a therapeutically active compound, or to a therapeutically active composition (comprising one or more therapeutically active compounds). "Treatment" / ”treating” refers to any rate of reduction, delaying or retardation of the progress of the disease or disorder, or a single symptom thereof, compared to the progress or expected progress of the disease or disorder, or single symptom thereof, when left untreated. This implies that a therapeutic modality on its own may not result in a complete or partial response (or may even not result in anyresponse), but may, in particular when combined with other therapeutic modalities (such as otherimmunosuppressants or therapeutic modalities for treating or suppressing cancer or a tumor (or possibly other disease or disorder in case of CAR-Ms in which HPGDS expression or function is inhibited),contribute to a complete or partial response. More desirable, the treatment results in no / zero progressof the disease or disorder, or single symptom thereof (i.e. "inhibition" or “inhibition of progression”), or even in any rate of regression of the already developed disease or disorder, or single symptom thereof. “Suppression / suppressing” can in this context be understood to be comprised within the meaning of theterm “treatment / treating”. Treatment / treating also refers to achieving a significant amelioration of oneor more clinical symptoms associated with a disease or disorder, or of any single symptom thereof. Depending on the situation, the significant amelioration may be scored quantitatively or qualitatively. Qualitative criteria may e.g. by patient well-being. In the case of quantitative evaluation, the significant amelioration is typically a 10% or more, a 20% or more, a 25% or more, a 30% or more, a 40% or more, a 50% or more, a 60% or more, a 70% or more, a 75% or more, a 80% or more, a 95% or more, or a 100% improvement over the situation prior to treatment. The time-frame over which the improvement is evaluated will depend on the type of criteria / disease observed and can be determined by the person skilled in the art. A "therapeutically effective amount" refers to an amount of a therapeutic agent to treat, inhibit or prevent a disease or disorder in a subject (such as a mammal). Efficacy in vivo can, e.g., be measured by assessing the duration of survival (e.g. overall survival), time to disease progression (TTP), response rates (e.g., complete response and partial response, stable disease), length of progression-free survival (PFS), duration of response, and / or quality of life. The term “effective amount” or “therapeutically effective amount” may depend on the dosing regimen of the agent / therapeutic agent or composition comprising the agent / therapeutic agent (e.g. medicament or pharmaceutical composition). The effective amount will generally depend on and / or will need adjustment to the mode of contacting or administration. The effective amount of the agent or composition comprising the agent is the amount required to obtain the desired clinical outcome or therapeutic effect without causing significant or unnecessary toxic effects (often expressed as maximum tolerable dose, MTD). To obtain or maintain the effective amount, the agent or composition comprising MaMa / HPGDS / 822 the agent may be administered as a single dose or in multiple doses. The effective amount may further vary depending on the severity of the condition that needs to be treated; this may depend on the overall health and physical condition of the subject or patient and usually the treating doctor’s or physician’s assessment will be required to establish what is the effective amount. The effective amount may further be obtained by a combination of different types of contacting or administration. The aspects and embodiments described above in general may comprise the administration of one ormore therapeutic compounds to a subject (such as a mammal) in need thereof or in need of treatment.In general a (therapeutically) effective amount of (a) therapeutic compound(s) is administered to the mammal in need thereof in order to obtain the described clinical response(s). “Administering” means any mode of contacting that results in interaction between an agent or composition comprising the agent (such as a medicament or pharmaceutical composition) and an object (e.g. cell, tissue, organ, body lumen) with which said agent or composition is contacted. The interaction between the agent or composition and the object can occur starting immediately or nearly immediately with the administration of the agent or composition, can occur over an extended time period (starting immediately or nearly immediately with the administration of the agent or composition), or can be delayed relative to the time of administration of the agent or composition. More specifically the “contacting” results in delivering an effective amount of the agent or composition comprising the agent to the object. Further anti-tumor or anti-cancer agentWithout being exhaustive, further antitumor, anticancer or antineoplastic agents (other than inhibitorsof HPGDS and immune checkpoint inhibitors) include alkylating agents (nitrogen mustards: melphalan,cyclophosphamide, ifosfamide; nitrosoureas; alkylsulfonates; ethyleneimines; triazene; methyl hydrazines; platinum coordination complexes: cisplatin, carboplatin, oxaliplatin), antimetabolites (folate antagonists: methotrexate; purine antagonists; pyrimidine antagonists: 5-fluorouracil, cytarabibe), natural plant products (Vinca alkaloids: vincristine, vinblastine; taxanes: paclitaxel, docetaxel; epipodophyllotoxins: etoposide; camptothecins: irinotecan), natural microorganism products (antibiotics: doxorubicin, bleomycin; enzymes: L-asparaginase), hormones and antagonists (corticosteroids: prednisone, dexamethasone; estrogens: ethinyloestradiol; antiestrogens: tamoxifen; progesteron derivative: megestrol acetate; androgen: testosterone propionate; antiandrogen: flutamide , bicalutamide; aromatase inhibitor: letrozole, anastrazole; 5-alpha reductase inhibitor: finasteride; GnRH analogue: leuprolide, buserelin; growth hormone, glucagon and insulin inhibitor: octreotide). Other antineoplastic or antitumor agents include hydroxyurea, imatinib mesylate, epirubicin, bortezomib, zoledronic acid, geftinib, leucovorin, pamidronate, and gemcitabine. MaMa / HPGDS / 822 Without being exhaustive, further antitumor, anticancer or antineoplastic antibodies (antibody therapy) include rituximab, bevacizumab, ibritumomab tiuxetan, tositumomab, brentuximab vedotin, gemtuzumab ozogamicin, alemtuzumab, adecatumumab, labetuzumab, pemtumomab, oregovomab, minretumomab, farletuzumab, etaracizumab, volociximab, cetuximab, panitumumab, nimotuzumab, trastuzumab, pertuzumab, mapatumumab, denosumab, and sibrotuzumab. A particular class of antitumor, anticancer or antineoplastic agents are designed to stimulate the immune system (immune checkpoint or other immunostimulating therapy). These include so-called immune checkpoint inhibitors or inhibitors of co-inhibitory receptors and include PD-1 (Programmed cell death 1) inhibitors (e.g. pembrolizumab, nivolumab, pidilizumab), PD-L1 (Programmed cell death 1 ligand) inhibitors (e.g. atezolizumab, avelumab, durvalumab), CTLA-4 (Cytotoxic T-lymphocyte associated protein 4; CD152) inhibitors (e.g. ipilimumab, tremelimumab) (e.g. Sharon et al. 2014, Chin J Canc 33:434-444). Inhibition of other co-inhibitory receptors under evaluation as antitumor, anticancer or antineoplastic agents include inhibitors of Lag-3 (lymphocyte activation gene 3), Tim-3 (T cell immunoglobulin 3) and TIGIT (T cell immunoglobulin and ITM domain) (Anderson et al.2016, Immunity44:989-1004). Stimulation of members of the TNFR superfamily of co-receptors expressed on T-cells,such as stimulation of 4-1BB (CD137), OX40 (CD134) or GITR (glucocorticoid-induced TNF receptor family-related gene), is also evaluated for antitumor, anticancer or antineoplastic therapy (Peggs et al. 2009, Clin Exp Immunol 157:9-19).Further antitumor, anticancer or antineoplastic agents include immune-stimulating agents such as - orneo-epitope cancer vaccines (neo-antigen or neo-epitope vaccination; based on the patient’s sequencing data to look for tumor-specific mutations, thus leading to a form of personalized immunotherapy; Kaiser 2017, Science 356:112; Sahin et al.2017, Nature 547:222-226) and some Toll-like receptor (TLR) ligands (Kaczanowska et al.2013, J Leukoc Biol 93:847-863). Yet further antitumor, anticancer or antineoplastic agents include oncolytic viruses (oncolytic virus therapy) such as employed in oncolytic virus immunotherapy (Kaufman et al.2015, Nat Rev Drug Discov 14:642-662), any other cancer vaccine (cancer vaccine administration; Guo et al.2013, Adv Cancer Res 119:421-475), and any other anticancer nucleic acid therapy. Gene expression and quantification of gene expression The term "level of expression" or "expression level" generally refers to the amount of an expressed geneor (bio)marker in a biological sample. As used herein, "expression" may refer to transcription into apolynucleotide, translation into a polypeptide, or even polynucleotide modifications (e.g. alternative splicing) and / or polypeptide modifications (e.g., posttranslational modification of a polypeptide). Fragments of the transcribed polynucleotide, the translated polypeptide, or polynucleotide and / or MaMa / HPGDS / 822 polypeptide modifications (e.g., posttranslational modification of a polypeptide) are also regarded as expressed whether they originate from a transcript generated by alternative splicing or a degradedtranscript, or from a post-translational processing of the polypeptide, e.g., by proteolysis. "Expressedgenes" include those that are transcribed into a polynucleotide as mRNA and then translated into a polypeptide, and also those that are transcribed into RNA but not translated into a polypeptide (for example, transfer and ribosomal RNAs, long non-coding RNA, microRNA or miRNA)."Increased / higher expression," "increased / higher expression level," "increased / higher levels," "elevatedexpression," "elevated expression levels," or "elevated levels" refers to an increased / higher expressionor to increased / higher levels of a (bio)marker in an individual relative to a suitable control or standard.The term "detection" includes any means of detecting, including direct and indirect detection. The term”marker” or "biomarker" as used herein refers to an indicator molecule or set of indicator molecules(e.g., predictive, diagnostic, and / or prognostic indicator), which can be detected in a sample. The biomarker may be a predictive biomarker and serve as an indicator of the likelihood of sensitivity orbenefit to therapeutic treatment of a patient having a particular disease or disorder (e.g., a proliferativecell disorder (e.g., cancer)) to treatment (e.g. with an inhibitor of HPGDS and / or with an immunecheckpoint blocker). Biomarkers in general include, but are not limited to, polynucleotides (e.g., DNA and / or RNA (e.g., mRNA)), polynucleotide copy number alterations (e.g., DNA copy numbers), polypeptides, polypeptide and polynucleotide modifications (e.g., post-translational modifications, nucleotide substitutions, nucleotide insertions or deletions (indels)), carbohydrates, and / or glycolipid- based molecular markers. In some embodiments, a biomarker is a gene. The "amount" or "level" of a biomarker, as used herein, is a detectable level in a biological sample. These can be measured by methods known to one skilled in the art and also disclosed herein. In first instance, methodologies for determining gene expression by means of determining transcript levels, also referred to as transcriptome analysis or analysis of the transcriptome, is described in more detail. Any such gene detection or gene expression detection method is starting from an analyte nucleic acid (i.e. the nucleic acid of interest (which does not necessarily need to be the whole nucleic acid of interest, parts of such nucleic acids can suffice for determining expression) and of which the amount isto be determined) and may be defined as comprising one or more steps of, for instance,- a step of isolating RNA from a (biological) sample (wherein a fraction of the isolated RNA is theanalyte strand);- a step of reverse transcribing the RNA obtained from the biological sample into DNA;- a step of amplifying the isolated DNA; and / or MaMa / HPGDS / 822- a step of quantifying the isolated RNA, the DNA obtained after reverse transcription, or the amplifiedDNA. In case an amplified DNA is quantified, this quantification step can be performed concurrent with the amplification of the DNA, or is performed after the amplification of the DNA. The quantification of gene expression or the determination of gene expression levels may be based on at least one of an amplification reaction, a sequencing reaction, a melting reaction, a hybridizationreaction or a reverse hybridization reaction. Quantification of gene expression can further involve anormalization step, wherein levels of expression of a gene of interest are normalized to e.g. levels of expression of a housekeeping gene or of a gene of which the expression is relatively constant under different conditions.This disclosure covers methods which include measurement, determination, assessment, analysis,detection or quantification of nucleic acids corresponding to one or more gene(s) or (bio)markers asdefined herein (more specifically HPGDS, PD1). In any of these methods the detection can comprise astep such as a nucleic acid amplification reaction, a nucleic acid sequencing reaction, a melting reaction, a hybridization reaction to a nucleic acid, or a reverse hybridization reaction to a nucleic acid, or a combination of such steps. Often one or more artificial, man-made, or non-naturally occurring oligonucleotide is used in such method. In particular, such oligonucleotides can comprise besides ribonucleic acid monomers or deoxyribonucleic acid monomers: one or more modified nucleotide bases, one or more modified nucleotide sugars, one or more labelled nucleotides, one or more peptide nucleic acid monomers, one or more locked nucleic acid monomers, the backbone of such oligonucleotide can be modified, and / or non-glycosidic bonds may link two adjacent nucleotides. Such oligonucleotides may further comprise a modification for attachment to a solid support, e.g., an amine-, thiol-, 3-'propanolamine or acrydite- modification of the oligonucleotide, or may comprise the addition of a homopolymeric tail (for instance an oligo(dT)-tail added enzymatically via a terminal transferase enzyme or added synthetically) to the oligonucleotide. If said homopolymeric tail is positioned at the 3'-terminus of the oligonucleotide or if any other 3'-terminal modification preventing enzymatic extension is incorporated in the oligonucleotide, the priming capacity of the oligonucleotide can be decreased or abolished. Such oligonucleotides may also comprise a hairpin structure at either end. Terminal extension of such oligonucleotide may be useful for, e.g., specifically hybridizing with another nucleic acid molecule (e.g. when functioning as capture probe), and / or for facilitating attachment of said oligonucleotide to a solid support, and / or for modification of said tailed oligonucleotide by an enzyme, ribozyme or DNAzyme and / or for purposes of sequencing (e.g. addition of adaptor oligonucleotides in the preparation of a next- MaMa / HPGDS / 822 generation sequencing library). Such oligonucleotides may be modified in order to detect (the levels of) a target nucleotide sequence and / or to facilitate in any way such detection. Such modifications include labelling with a single label, with two different labels (for instance two fluorophores or one fluorophore and one quencher), the attachment of a different 'universal' tail to two probes or primers hybridizing adjacent or in close proximity to each other with the target nucleotide sequence, the incorporation of a target-specific sequence in a hairpin oligonucleotide (for instance Molecular Beacon-type primer), the tailing of such a hairpin oligonucleotide with a 'universal' tail (for instance Sunrise-type probe and Amplifluor TM -type primer). A special type of hairpin oligonucleotide incorporates in the hairpin a sequence capable of hybridizing to part of the newly amplified target DNA. Amplification of the hairpin is prevented by the incorporation of a blocking non-amplifiable monomer (such as hexethylene glycol). A fluorescent signal is generated after opening of the hairpin due to hybridization of the hairpin loop with the amplified target DNA. This type of hairpin oligonucleotide is known as scorpion primers (Whitcombe et al.1999, Nat Biotechnol 17:804-807). Another special type of oligonucleotide is a padlock oligonucleotide (or circularizable, open circle, or C-oligonucleotide) that are used in RCA (rolling circle amplification). Such oligonucleotides may also comprise a 3'-terminal mismatching nucleotide and / or, optionally, a 3'-proximal mismatching nucleotide, which can be particularly useful for performing polymorphism-specific PCR and LCR (ligase chain reaction) or any modification of PCR or LCR. Such oligonucleotide may can comprise or consist of at least and / or comprise or consist of up to 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200 or more contiguous nucleotides. The analyte nucleic acid, in particular the analyte nucleic acid of a biomarker of interest can be any type of nucleic acid, which will be dependent on the manipulation steps (such as isolation and / or purification and / or duplication, multiplication or amplification) applied to the nucleic acid of the gene of interest in the biological sample; as such it can be DNA, RNA, cDNA, may comprise modified nucleotides, or may behybrids of DNA and / or RNA and / or modified nucleotides, and can be single- or double-stranded or maybe a triplex-forming nucleic acid. The artificial, man-made, non-naturally occurring oligonucleotide(s) as applied in the above detection methods can be probe(s) or a primer(s), or a combination of both. A probe capable of specifically hybridizing with a target nucleic acid is an oligonucleotide mainly hybridizing to one specific nucleic acid sequence in a mixture of many different nucleic acid sequences. Specific hybridization is meant to result, upon detection of the specifically formed hybrids, in a signal-to-noise ratio (wherein the signal represents specific hybridization and the noise represents unspecifichybridization) sufficiently high to enable unambiguous detection of said specific hybrids. In a specific MaMa / HPGDS / 822 case specific hybridization allows discrimination of up to a single nucleotide mismatch between the probe and the target nucleic acids. Conditions allowing specific hybridization generally are stringent but can obviously be varied depending on the complexity (size, GC-content, overall identity, etc.) of the probe(s) and / or target nucleic acid molecules. Specificity of a probe in hybridizing with a nucleic acid can be improved by introducing modified nucleotides in said probe. A primer capable of directing specific amplification of a target nucleic acid is the at least one oligonucleotide in a nucleic acid amplification reaction mixture that is required to obtain specific amplification of a target nucleic acid. Nucleic acid amplification can be linear or exponential and canresult in an amplified single nucleic acid of a single- or double-stranded nucleic acid or can result in bothstrands of a double-stranded nucleic acid. Specificity of a primer in directing amplification of a nucleic acid can be improved by introducing modified nucleotides in said primer. The fact that a primer does not have to match exactly with the corresponding template or target sequence to warrant specificamplification of said template or target sequence is amply documented in literature (for instance: Kwoket al.1990, Nucl Acids Res 18:999-1005. Primers as short as 8 nucleotides in length have been applied successfully in directing specific amplification of a target nucleic acid molecule (e.g. Majzoub et al.1983, J Biol Chem 258:14061-14064). A nucleotide is meant to include any naturally occurring nucleotide as well as any modified nucleotide wherein said modification can occur in the structure of the nucleotide base (modification relative to A, T, G, C, or U) and / or in the structure of the nucleotide sugar (modification relative to ribose or deoxyribose). Any of the modifications can be introduced in a nucleic acid or oligonucleotide to increase / decrease stability and / or reactivity of the nucleic acid or oligonucleotide and / or for other purposes such as labelling of the nucleic acid or oligonucleotide. Modified nucleotides include phosphorothioates, alkylphosphorothioates, methylphosphonate, phosphoramidate, peptide nucleic acid monomers and locked nucleic acid monomers, cyclic nucleotides, and labelled nucleotides (i.e. nucleotides conjugated to a label which can be isotopic (<32>P, <35>S, etc.) or non-isotopic (biotin, digoxigenin, phosphorescent labels, fluorescent labels, fluorescence quenching moiety, etc.)). Other modifications are described higher (see description on oligonucleotides). Nucleotide acid amplification is meant to include all methods resulting in multiplication of the number of a target nucleic acid. Nucleotide sequence amplification methods include the polymerase chain reaction (PCR; DNA amplification), strand displacement amplification (SDA; DNA amplification), transcription-based amplification system (TAS; RNA amplification), self-sustained sequence replication (3SR; RNA amplification), nucleic acid sequence-based amplification (NASBA; RNA amplification), transcription-mediated amplification (TMA; RNA amplification), Qbeta-replicase-mediated amplification MaMa / HPGDS / 822 and run-off transcription. During amplification, the amplified products can be conveniently labelled either using labelled primers or by incorporating labelled nucleotides. The most widely spread nucleotide sequence amplification technique is PCR. The target DNA is exponentially amplified. Many methods rely on PCR including AFLP (amplified fragment length polymorphism), IRS-PCR (interspersed repetitive sequence PCR), iPCR (inverse PCR), RAPD (rapid amplification of polymorphic DNA), RT-PCR (reverse transcription PCR) and real-time PCR. RT-PCR can be performed with a single thermostable enzyme having both reverse transcriptase and DNA polymerase activity (Myers et al. 1991, Biochem 30:7661-7666). Alternatively, a single tube-reaction with two enzymes (reverse transcriptase and thermostable DNA polymerase) is possible (Cusi et al. 1994, Biotechniques 17:1034-1036). Solid phases, solid matrices or solid supports on which molecules, e.g., nucleic acids, analyte nucleic acids and / or oligonucleotides as described hereinabove, may be bound (or captured, absorbed, adsorbed, linked, coated, immobilized; covalently or non-covalently) comprise beads or the wells or cups of microtiter plates, or may be in other forms, such as solid or hollow rods or pipettes, particles, e.g., from 0.1 µm to 5 mm in diameter (e.g. "latex" particles, protein particles, or any other synthetic or natural particulate material), microspheres or beads (e.g. protein A beads, magnetic beads). A solid phase may be of a plastic or polymeric material such as nitrocellulose, polyvinyl chloride, polystyrene, polyamide, polyvinylidene fluoride or other synthetic polymers. Other solid phases include membranes, sheets, strips, films and coatings of any porous, fibrous or bibulous material such as nylon, polyvinyl chloride or another synthetic polymer, a natural polymer (or a derivative thereof) such as cellulose (or a derivative thereof such as cellulose acetate or nitrocellulose). Fibers or slides of glass, fused silica or quartz are other examples of solid supports. Paper, e.g., diazotized paper may also be applied as solid phase. Clearly, molecules such as nucleic acids, analyte nucleic acids and / or oligonucleotides as described hereinabove, may be bound, captured, absorbed, adsorbed, linked or coated to any solid phase suitable for use in hybridization assay (irrespective of the format, for instance capture assay, reverse hybridization assay, or dynamic allele-specific hybridization (DASH)). Said molecules, such as nucleic acids, analyte nucleic acids and / or oligonucleotides as described hereinabove, can be present on a solid phase in defined zones such as spots or lines. Such solid phases may be incorporated in a component such as a cartridge of e.g. an assay device. Any of the solid phases described above can be developed, e.g. automatically developed in an assay device. Quantification of amplified DNA can be performed concurrent with or during the amplification. Techniques include real-time PCR or (semi-)quantitative polymerase chain reaction (qPCR). One common method includes measurement of a non-sequence specific fluorescent dye (e.g. SYBR Green) intercalating in any double-stranded DNA. Quantification of multiple amplicons with different melting MaMa / HPGDS / 822 points can be followed simultaneously by means of following or analyzing the melting reaction (melting curve analysis or melt curve analysis; which can be performed at high resolution, see, e.g. Wittwer et al.2003, Clin Chem 843-860; an alternative method is denaturing gel gradient electrophoresis, DGGE; bothmethods were compared in e.g. Tindall et al.2009, Hum Mutat 30:857-859). Another common method includes measurement of sequence-specific labelled probe bound to its complementary sequence; such probe also carries a quencher and the label is only measurable upon exonucleolytic release from the probe (hydrolysis probes such as TaqMan probes) or upon hybridization with the target sequence (hairpin probes such as molecular beacons which carry an internally quenched fluorophore whose fluorescence is restored upon unfolding the hairpin). This latter method allows for multiplexing by e.g. using mixtures of probes each tagged with a different label e.g. fluorescing at a different wavelength. Exciton-controlled hybridization-sensitivefluorescent oligonucleotide (ECHO) probes also allow for multiplexing. The hybridization-sensitive fluorescence emission of ECHO probes and the further modification of probes have made possible multicolor RNA imaging in living cells and facile detection of gene polymorphisms (Okamoto 2011, Chem Soc Rev, 40:5815–5828). Other methods of quantifying expression include SAGE (Serial Analysis of Gene Expression) and MPSS (Massively Parallel Signature Sequencing), each involving reverse-transcription of RNA. With "assaying" or "determining" or “detecting” and the like (e.g. assessing, measuring) is meant that a biological sample, suspected of comprising a target nucleic acid (such as a nucleic acid of a biomarker of interest as described herein), is processed as to generate a readable signal in case the target nucleic acid is actually present in the biological sample. Such processing may include, as described above, a step of producing an analyte nucleic acid. Simple detection of a produced readable signal indicates the presence of a target or analyte nucleic acid in the biological sample. When in addition the amplitude of the produced readable signal is determined, this allows for quantification of levels of a target or analyte nucleic acid as present in a biological sample. In particular, the readable signal may be a signal-to-noise ratio (wherein the signal represents specific detection and the noise represents unspecific detection) of an assay optimized to yield signal-to-noiseratios sufficiently high to enable unambiguous detection and / or quantification of the target nucleic acid.The noise signal, or background signal, can be determined e.g. on biological samples not comprising the target or analyte nucleic acid of interest, e.g. control samples, or comprising the required reference level of the target or analyte nucleic acid of interest, e.g. reference samples. Such noise or background signal may also serve as comparator value for determining an increase or decrease of the level of a target oranalyte nucleic acid in the biological sample, e.g. in a biological sample taken from a subject sufferingfrom a disease or disorder, further e.g. before start of a treatment and during treatment. MaMa / HPGDS / 822 The readable signal may be produced with all required components in solution or may be produced with some of the required components in solution and some bound to a solid support. Said signals include,e.g., fluorescent signals, (chemi)luminescent signals, phosphorescence signals, radiation signals, light orcolor signals, optical density signals, hybridization signals, mass spectrometric signals, spectrometric signals, chromatographic signals, electric signals, electronic signals, electrophoretic signals, real-time PCR signals, PCR signals, LCR signals, Invader-assay signals, sequencing signals (by any method such as Sanger dideoxy sequencing, pyrosequencing, 454 sequencing, single-base extension sequencing,sequencing by ligation, sequencing by synthesis, “next-generation” sequencing (NGS) (van Dijk et al.2014, Trends Genet 30:418-426)), nanopore sequencing, melting curve signals etc. An assay may be runautomatically or semi-automatically in an assay device. In view of its relatively low costs compared to e.g. very costly cancer therapies, NGS is finding its way to routine clinical care (Ratner 2018, Nature Biotechnol 36:484). Specific hybridization of an oligonucleotide (whether or not comprising one or more modified nucleotides) to its target sequence is to be understood to occur under stringent conditions as generally known in the art (e.g. Sambrook et al. 1989. Molecular Cloning. A laboratory manual. CSHL Press). However, depending to the hybridization solution (SSC, SSPE, etc.), oligonucleotides should be hybridized at their appropriate temperature in order to attain sufficient specificity. In order to allow hybridization to occur, the target nucleic acid molecules are generally thermally, chemically (e.g. by NaOH) or electrochemically denatured to melt a double strand into two single strands and / or to remove hairpins or other secondary structures from single stranded nucleic acids. The stringency of hybridization is influenced by conditions such as temperature, salt concentration and hybridization buffer composition. High stringency conditions for hybridization include high temperature and / or low salt concentration (salts include NaCl and Na3-citrate) and / or the inclusion of formamide in the hybridization buffer and / or lowering the concentration of compounds such as SDS (detergent) in the hybridization buffer and / or exclusion of compounds such as dextran sulfate or polyethylene glycol (promoting molecular crowding) from the hybridization buffer. Conventional hybridization conditions are described in e.g. Sambrook et al. 1989 (Molecular Cloning. A laboratory manual. CSHL Press) but the skilled craftsman will appreciate that numerous different hybridization conditions can be designed in function of the known or the expected homology and / or length of the nucleic acid sequence. Generally, for hybridizations with DNA oligonucleotides without formamide, a temperature of 68 DEG C, and for hybridization with formamide, 50% (v / v), a temperature of 42 DEG C is recommended. For hybridizations with oligonucleotides, the optimal conditions (formamide concentration and / or temperature) dependon the length and base composition of the probe and must be determined individually. In general,optimal hybridization for oligonucleotides of about 10 to 50 bases in length occurs approximately 5 DEG MaMa / HPGDS / 822 C below the melting temperature for a given duplex. Incubation at temperatures below the optimum may allow mismatched sequences to hybridize and can therefor result in reduced specificity. When using RNA oligonucleotides with formamide (50% v / v) it is recommend to use a hybridization temperature of 68 DEG C for detection of target RNA and of 50 DEG C for detection of target DNA. Alternatively, a high SDS hybridization solution can be utilized (Church et al.1984, Proc Natl Acad Sci USA 81:1991-1995). The specificity of hybridization can furthermore be ensured through the presence of a crosslinking moiety on the oligonucleotide (e.g. Huan et al. 2000, Biotechniques 28: 254-255; WO00 / 14281). Said crosslinking moiety enables covalent linking of the oligonucleotide with the target nucleotide sequence and hence allows stringent washing conditions. Such a crosslinking oligonucleotide can furthermore comprise another label suitable for detection / quantification of the oligonucleotide hybridized to the target.RPKM (Reads Per Kilobase Million) is often used as measure for expression. FPKM (Fragments PerKilobase Million) is very similar to RPKM; whereas RPKM was designed for single-end RNA-seq (everyread corresponded to a single sequenced fragment), FPKM was designed for paired-end RNA-seq. With paired-end RNA-seq, two reads can correspond to a single fragment, or, if one read in the pair did not map, one read can correspond to a single fragment. The only difference between RPKM and FPKM is that FPKM takes into account that two reads can map to one fragment (and so it doesn’t count this fragment twice). When using RNA-seq, reporting or results often is in RPKM (Reads Per Kilobase Million) or FPKM (Fragments Per Kilobase Million). Whatever metric used (another alternative for example is TPM(Transcripts Per Kilobase Million)), such metric is attempting to normalize for sequencing depth and genelength and provide a measure for quantifying transcript levels / gene expression / expression units. Next to methodologies for determining gene expression by means of determining transcript levels (transcriptome analysis), it is also possible to quantify gene expression by means of proteomic analysis(proteome analysis or analysis of the proteome). Classical proteomic analysis methods include ELISA,western blotting, mass spectrometry, chromatographic separation, immunohistochemistry, cell sorting (based on cell surface marker(s)) etc. Although not necessarily required, it can be advantageous to rely on multiplexed cytometry methods that can be performed directly on, e.g., a section of a cancer tissue biopsy (Formalin-Fixed Paraffin-Embedded (FFPE), fresh frozen (FF), …). Multiplexed cytometry methods, as well as some predictive cancer biomarkers identified using such methodology, have been reviewed by e.g. Fan et al.2020 (Cancer Communications 40:135-153) and have emerged with the advent of more sophisticated imaging techniques (e.g. cyclic immunofluorescence, tyramide-based immunofluorescence, epitope-targeted mass spectrometry, RNA detection) and standardized quantification methodologies. Such multiplexed cytometry methods include multiplex immunocytochemistry (mICH), imaging mass spectrometry, multiplexed ion beam imaging, MaMa / HPGDS / 822 chipcytometry, nucleotide (DNA / RNA)-barcoding-based mICH, and digital spacing profiling. Anothertechnique involving proteomic analysis is Cellular Indexing of Transcriptomes and Epitopesby Sequencing (CITE-seq).SequencingPolynucleotide sequence determination is a common step in some of the methods as applied in thecurrent disclosure. In general, sequencing methods may include, but are not limited to: high-throughput sequencing, pyrosequencing, sequencing-by-synthesis, single-molecule sequencing, nanopore sequencing, semiconductor sequencing, sequencing-by-ligation, sequencing-by-hybridization, RNA-Seq (Illumina), Digital Gene Expression (Helicos), Next generation sequencing, Single Molecule Sequencing by Synthesis(SMSS) (Helicos), massively- parallel sequencing, Clonal Single Molecule Array (Solexa), shotgunsequencing, Maxam- Gilbert or Sanger sequencing, primer walking, sequencing using PacBio, SOLiD, IonTorrent, or Nanopore platforms, short read sequencing, long read sequencing, and any other sequencingmethods known in the art. The sequencing method can be massively parallel sequencing, that is, simultaneously (or in rapid succession) sequencing any of at least 100, 1000, 10,000, 100,000, 1 million, 10 million, 100 million, 1 billion, or 10 billion polynucleotide molecules. Certain DNA sequencing methods may rely on the capture of polynucleotides of interest such as to enrich for these sequences of interest. Polynucleotide or sequence capture typically involves the use of oligonucleotide probes that hybridize to the polynucleotide or sequence of interest. A probe set strategy can involve tiling the probes across a region of interest (complete or partial tiling of the target sequence with probes). Such probes can be, e.g., 10 to 400 or about 400 bases long, 10 to 300 or about 300 bases long, 10 to 200 or about 200 bases long, 10 to 100 or about 100 bases long, 10 to 80 or about 80 bases long, 10 to 60 or about 60 bases long, Such probes may comprise at least one or a set of oligonucleotides of 10 to 60 bases or nucleotides long and / or comprise at least one or a set of oligonucleotides of 15 to 120 bases or nucleotides long. Any set of such oligonucleotide probes can have a depth of about 0.1x, 0.2x, 0.3x, 0.4 x, 0.5x, 0.1x to 0.5x, 1x 2x, 3x, 4x, 5x, 6x, 8x, 9x, 10x, 15x, 20x, 50x or more. Enriched nucleic acid molecules can be representative of a nucleic acid features of interest such as, but notnecessarily limited to the HPGDS gene markers and macrophage markers as described herein.Sequencing depth refers to the number of times a locus is covered by a sequence read aligned to the locus. A locus can be as small as a nucleotide, as large as a chromosome arm, or as large as the entire genome. Sequencing depth can be expressed as e.g.10x, 50x, 100x, where “x” refers to the number of times a locus is covered by a sequence read. Sequencing depth can also be applied to multiple loci, or to the whole genome, in which case “x” can refer to the mean number of times the loci, or whole genome,is sequenced. Ultra-deep sequencing refers to a sequencing depth of at least 100x. Sequencing depth MaMa / HPGDS / 822 usually increases with decreasing amounts of analyte strand; the sequencing depth is therefore expected to be higher in case of analyzing cell-free DNA compared to analyzing nucleic acids isolated from a tumor biopsy. Shallow whole genome sequencing, low coverage whole genome sequencing, or ultra-low pass whole genome sequencing in general refers to short-read sequencing of genomes at low coverage, typically less than 3x coverage, less than 2x coverage, less than 1x coverage, such as 0.1x to 1x coverage, such as 0.1x to 0.8x coverage, such as 0.1x to 0.6x coverage, such as 0.1x to 0.5x coverage, such as 0.1x to 0.4x coverage, such as 0.1x to 0.3x coverage, such as 0.9x coverage, 0.8x coverage, 0.7x coverage, 0.6x coverage, 0.5x coverage, 0.4x coverage, 0.3x coverage, 0.2x coverage or 0.1x coverage, such as 0.1x coverage or less. Sequencing coverage can also be expressed as average sequencing coverage. Low coverage in the context of sequencing thus can also refer to typically on average less than 3x coverage, on average less than 2x coverage, on average less than 1x coverage, such as on average 0.1x to 1x coverage, such as on average 0.1x to 0.8x coverage, such as on average 0.1x to 0.6x coverage, such as on average 0.1x to 0.5x coverage, such as on average 0.1x to 0.4x coverage, such as on average 0.1x to 0.3x coverage, such as on average 0.9x coverage, on average 0.8x coverage, on average 0.7x coverage, on average 0.6x coverage, on average 0.5x coverage, on average 0.4x coverage, on average 0.3x coverage, on average 0.2x coverage or on average 0.1x coverage, such as on average 0.1x coverage or less. By performing shallow whole genome sequencing, low coverage whole genome sequencing, or ultra-low pass whole genome sequencing, each sample is subjected to a small amount of sequencing, allowing application of whole genome sequencing to many samples at low cost per sample. A sequence read is a string of nucleotides sequenced from a part or all of a nucleic acid molecule. A sequence read may be a short string of nucleotides (e.g.20 to 150 nucleotides, around 50 nucleotides) sequenced from a nucleic acid (fragment). Sequence reads may be obtained at one end of a nucleic acid (fragment) or from both ends of a nucleic acid (fragment). Sequence reads may be obtained by e.g. applying a sequencing technique to the nucleic acid (fragment), by hybridization arrays or capture probes, by amplification techniques (e.g. PCR, linear amplification, isothermal amplification) such as amplification techniques using a single primer. Thus, obtaining information from the nucleic acid molecules present in a biological sample may include a step of preparing a sequencing library using the nucleic acid molecules isolated from the biological sample. The preparation of such sequencing library may include a step of DNA amplification, or may,alternatively, not include a step of DNA amplification. Obtaining information from the nucleic acidmolecules present in a biological sample may include obtaining DNA sequence reads. Obtaining information from the nucleic acid molecules (e.g. cfDNA molecules) present in a biological sample may MaMa / HPGDS / 822 include the step of aligning the plurality of (DNA) sequence reads to a reference genome to determine the genomic positions of each (individual) sequence read of the plurality of sequence reads. In view ofthe size of the reference genome and the number of sequence reads in a plurality of sequence reads,the sequence reads are optionally received at a computer system.Spatial detection methods Spatial proteomics A good overview of spatial detection methods is provided by Lewis et al.2021 (Nature Methods 18:997- 1012) with Figures 3 to 5 therein summarizing the described methods and their performance.The most classical spatial detection methods are histopathological staining (e.g. haematoxylin and eosinstaining) and immunohistochemical staining. Histopathological staining provides information on different tissue structures and possible abnormalities therein. Immunohistochemical (IHC) staining involves binding of antibodies to target proteins of interest, usually these (primary) antibodies are unlabelled and (primary) antibodies bound to its target in e.g. a tissue section are subsequently detected by binding of a labelled, e.g. fluorescently labelled, (secondary) antibody that binds to the (primary) antibody bound to the target protein of interest. In multiplexed IHC (mIHC) usually up to 4 or 5 target proteins of interest can be detected simultaneously. In modern mIHC, iterative cycles of target proteinof interest detection are applied. This involves successive cycles of antibody binding and stripping of theantibody or stripping or bleaching of the antibody-labels. Alternatively, a pool of DNA-barcoded antibodies is applied and iterative hybridization with differently labelled oligonucleotides is performed. As a result, some of these techniques can detect up to 100 different proteins can be detected in a single tissue sample. Non-iterative methods of target protein of interest detection involve binding of metal isotope-labelled antibodies that are subsequently detected by mass spectrometry upon release from a sample by means of tissue ablation with a laser beam (IMC: imaging mass cytometry) or tissue ionization with an ion beam (MIBI: multiplexed ion beam imaging). These techniques can detect up to 40 different proteins can be detected in a single tissue sample. IMC also allows for detection of an RNA target of interest. Concurrent quantitation of more than 40 proteins of interest is furthermore possible by quantitative analysis (involving sequencing) of oligonucleotides cleaved off from oligo-nucleotide labelled primary antibodies, this in a technique called digital spatial profiling (DSP). DSP also allows for detection of anRNA target of interest. These spatial proteomic techniques have been summarized in e.g. Figure 3 ofLewis et al.2021 (Nature Methods 18:997-1012). MaMa / HPGDS / 822 Spatial transcriptomics Spatial transcriptomics rely on direct detection of transcripts of interest with fluorescently labelled probes, the technology called fluorescent in situ hybridization (FISH). Many different FISH-based spatial transcriptomic methods have been developed and include iterative hybridization or bleaching or destruction of the labelled probes. Some of the FISH-based spatial transcriptomic methods allow for detection of up to 10000 different transcripts (summarized in e.g. Figure 4 of Lewis et al.2021 (Nature Methods 18:997-1012). Another series of spatial transcriptomic methods involve sequencing. In vitro methods (e.g. on a tissue sample) include laser capture microdissection (LCM) methods, methodsincluding an mRNA capture step, and microfluidic-based methods – all have been reported to allow fordetection of 10000 or more targets. In situ methods include in situ sequencing and fluorescence in situsequencing methods. The sequencing technique can rely on sequence-by-ligation or sequence-by- hybridization methodologies. Again, some of these methods have been reported to allow for detection of 10000 or more targets (incompletely summarized in e.g. Figure 5 of Lewis et al.2021 (Nature Methods 18:997-1012). Tumor, cancer, neoplasm The terms tumor and cancer are sometimes used interchangeably but can be distinguished from each other. A tumor refers to “a mass” which can be benign (more or less harmless) or malignant (cancerous). A cancer is a threatening type of tumor. A tumor is sometimes referred to as a neoplasm: an abnormal cell growth, usually faster compared to growth of normal cells. Benign tumors or neoplasms are non- malignant / non-cancerous, are usually localized and usually do not spread / metastasize to other locations. Because of their size, they can affect neighboring organs and may therefore need removal and / or treatment. A cancer, malignant tumor or malignant neoplasm is cancerous in nature, can metastasize, and sometimes re-occurs at the site from which it was removed (relapse). The initial site where a cancer starts to develop gives rise to the primary cancer. When cancer cells break away from the primary cancer (“seed”), they can move (via blood or lymph fluid) to another site even remote from the initial site. If the other site allows settlement and growth of these moving cancer cells, a new cancer, called secondary cancer, can emerge (“soil”). The process leading to secondary cancer is also termed metastasis, and secondary cancers are also termed metastases. For instance, liver cancer can arise as primary cancer, but can also be a secondary cancer originating from a primary breast cancer, bowel cancer or lung cancer; some types of cancer show an organ-specific pattern of metastasis. Most cancer deaths are in fact caused by metastases, rather than by primary tumors (Chambers et al.2002, Nature Rev Cancer2:563-572). MaMa / HPGDS / 822 Cancer is referred to in general terms herein. More in particular, the cancer or tumor is a primary canceror tumor. Not mutually exclusive, the cancer or tumor more in particular is a solid cancer or tumor. Morespecifically, the cancer is melanoma or hepatocellular carcinoma (HCC), such as advanced HCC (aHCC) orpancreatic cancer. Immune checkpoint inhibitors / blockers (ICIs / ICBs / CPIs) Immune checkpoints antagonists or inhibitors as referred to herein include the cell surface protein cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed cell death protein-1 (PD-1) and their respective ligands. CTLA-4 binds to its co-receptor B7-1 (CD80) or B7-2 (CD86); PD-1 binds to its ligands PD-L1 (B7- H10) and PD-L2 (B7-DC). Other immune checkpoint inhibitors include the adenosine A2A receptor (A2AR), B7-H3 (or CD276), B7-H4 (or VTCN1), BTLA (or CD272), IDO (indoleamine 2,3-10 dioxygenase), KIR (killer-cell immunoglobulin-like receptor), LAG3 (lymphocyte activation gene-3), NOX2 (nicotinamide adenine dinucleotide phosphate (NADPH) oxidase isoform 2), TIM3 (T-cell immunoglobulin domain and mucin domain 3), VISTA (V-domain Ig suppressor of T cell activation), SIGLEC7 (sialic acid-binding immunoglobulin-type lectin 7, or CD328) and SIGLEC9 (sialic acid-binding immunoglobulin-type lectin 9, or CD329). In any of the above aspects, embodiments, and kits, the therapy comprising an ICI or therapy with an ICIcan in particular be a therapy comprising a combination in any way of two immune checkpoint inhibitors.In one embodiment these are each inhibiting a different immune checkpoint or a different immune checkpoint-ligand interaction. For instance, when an inhibitor of PD1 is selected as a first immune checkpoint inhibitor, the second immune checkpoint inhibitor could be an inhibitor of PDL1 or an inhibitor of PDL2. Such first and second immune checkpoint inhibitor are each inhibiting a different immune checkpoint protein. In a further non-limiting example, an inhibitor of PD1 is selected as a first immune checkpoint inhibitor, and as second immune checkpoint inhibitor an inhibitor different from an inhibitor of PDL1 and different from an inhibitor of PDL2 is selected, e.g. an inhibitor of CTLA-4 is selected. In this latter example, the first and second immune checkpoint inhibitor are not only each inhibiting a different immune checkpoint, but also each inhibiting a different immune checkpoint-ligand interaction. An overview of clinical developments in the field of immune checkpoint therapy is given by Fan et al. 2019 (Oncology Reports 41:3-14). Immune checkpoint inhibitors include, but are not limited to anti-PD- 1, anti-PD-L1 or anti-CTLA-4 antibodies. MaMa / HPGDS / 822 PD1 Aliases of PD1 provided in GeneCards® include PDCD1; Programmed Cell Death 1; Systemic Lupus Erythematosus Susceptibility 2; PD-1; CD279; HPD-1; SLEB2; and HPD-L. The genomic locations for the PDCD1 gene are chr2:241,849,881-241,858,908 (in GRCh38 / hg38) and chr2:242,792,033-242,801,060 (in GRCh37 / hg19). The GenBank reference PD1 mRNA sequence is known under accession no. NM_005018.3. Approved PD1-inhibiting antibodies include nivolumab, pembrolizumab, and cemiplimab; PD1-inhibiting antibodies under development include CT-011 (pidilizumab) and therapy with PD1-inhibiting antibodies is referred to herein as α-PD-1 therapy or α-PD1 therapy. PD1 siRNA and shRNA products are available through e.g. Origene. PD-L1 Aliases of PD-L1 provided in GeneCards® include CD274, Programmed Cell Death 1 Ligand 1, B7 Homolog 1, B7H1, PDL1, PDCD1 Ligand 1, PDCD1LG1, PDCD1L1, HPD-L1, B7-H1, B7-H, and Programmed Death Ligand 1. The genomic locations for the PDCD1 gene are chr9:5,450,503-5,470,567 (in GRCh38 / hg38) and chr9:5,450,503-5,470,567 (in GRCh37 / hg19). The GenBank reference PD1 mRNA sequence is knownunder accession no. NM_001267706.1, NM_001314029.2 and NM_014143.4. Approved PD-L1-inhibitingantibodies include atezolizumab, avelumab, and durvalumab. PD-L1 siRNA and shRNA products are available through e.g. Origene. CTLA4 Aliases of CTLA4 provided in GeneCards® include Cytotoxic T-Lymphocyte Associated Protein 4; CTLA-4; CD152; Insulin-Dependent Diabetes Mellitus 12; Cytotoxic T-Lymphocyte Protein 4; Celiac Disease 3; GSE; Ligand And Transmembrane Spliced Cytotoxic T Lymphocyte Associated Antigen 4; Cytotoxic T Lymphocyte Associated Antigen 4 Short Spliced Form; Cytotoxic T-Lymphocyte-Associated Serine Esterase-4; Cytotoxic T-Lymphocyte-Associated Antigen 4; CELIAC3; IDDM12; ALPS5; and GRD4. The genomic locations for the CTLA4 gene are chr2:203,867,771-203,873,965 (in GRCh38 / hg38) andchr2:204,732,509-204,738,683 (in GRCh37 / hg19). The GenBank reference CTLA4 mRNA sequences areknown under accession nos. NM_001037631.3 and NM_005214.5. Approved CTLA4-inhibitingantibodies include ipilumab; CTLA4-inhibiting antibodies under development include tremelimumab; therapy with CTLA4-inhibiting antibodies is referred to herein as α-CTLA4 therapy. CTLA4 siRNA and shRNA products are available through e.g. Origene. Combination, combination in any way “Combination”, “combination in any way” or “combination in any appropriate way” as referred to hereinis meant to refer to any sequence of administration of two (or more) therapeutic modalities, i.e. theadministration of the two (or more) therapeutic modalities can occur concurrently in time or separated MaMa / HPGDS / 822from each other by any amount of time; and / or “combination”, “combination in any way” or“combination in any appropriate way” as referred to herein can refer to the combined or separate formulation of the two (or more) therapeutic modalities, i.e. the two (or more) therapeutic modalitiescan be individually provided in separate vials or (other suitable) containers, or can be provided combinedin the same vial or (other suitable) container. When combined in the same vial or (other suitable)container, the two (or more) therapeutic modalities can each be provided in the same vial / containerchamber of a single-chamber vial / container or in the same vial / container chamber of a multi-chambervial / container; or can each be provided in a separate vial / container chamber of a multi-chambervial / container. Other DefinitionsThe present disclosure is described with respect to particular embodiments and with reference to certaindrawings but the disclosure is not limited thereto but only by the claims. Any reference signs in the claimsshall not be construed as limiting the scope. The drawings described are only schematic and are non- limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeableunder appropriate circumstances and that the embodiments of the current disclosure described hereinare capable of operation in other sequences than described or illustrated herein. Unless specifically defined herein, all terms used herein have the same meaning as they would to one skilled in the art of the current disclosure. Practitioners are particularly directed to Sambrook et al., Molecular Cloning: A Laboratory Manual, 4th ed., Cold Spring Harbor Press, Plainsview, New York (2012); and Ausubel et al., current Protocols in Molecular Biology (Supplement 100), John Wiley & Sons, New York (2012), for definitions and terms of the art. The definitions provided herein should not be construed to have a scope less than understood by a person of ordinary skill in the art. In any of the above, a “subject” in general is a mammalian species having (or having been diagnosed to have) a disease or disorder, in particular a cancer or a tumor. The mammalian species in general is a higher species including primates, cattle (e.g. cows, sheep, goats, pigs), horses, and pets (e.g. dogs, cats). In one embodiment the patient is a human subject or human patient. MaMa / HPGDS / 822 It is to be understood that although particular embodiments, specific configurations as well as materials and / or molecules, have been discussed herein for cells and methods according to the present disclosure, various changes or modifications in form and detail may be made without departing from the scope and spirit of this disclosure. The following examples are provided to better illustrate particular embodiments, and they should not be considered limiting the application. The application is limited only by the claims. In referring to genes or proteins herein, distinction between their respective annotation is not always made hereinabove or hereinafter. The content of the documents cited herein are incorporated by reference. EXAMPLES EXAMPLE 1. Identification of HPGDS expression on immunosuppressive tumor-associated macrophages (TAMs)A meta-analysis was performed by combining two publicly available pre- and post-treatment bulk RNA-sequencing datasets (RNA-Seq) of tumors responding and resistant to ^-PD1 treatment (Hugo et al.2016, Cell 165:35-44; Riaz et al.2017, Cell 171:934-949). For each individual dataset, a differential geneexpression analysis between tumors responsive to ^-PD1 treatment and non-responsive to ^-PD1treatment was performed including BRAF, NRAS and NF1 mutational status as a covariate. We thenranked genes by their log2 fold change and combined the resulting rank by calculating the median rank product to identify metabolic genes that were consistently associated with PD1 immunotherapy response. The rank-product meta-analysis on metabolic genes specifically identified Hematopoietic Prostaglandin D2 Synthase (HPGDS) as a potential top target. When we filtered the ranked gene list forgenes associated with arachidonic acid metabolism, HPGDS was again among the top candidates. Thearachidonic acid metabolism associated ranked gene list was subsequently visualized using the R package ggplot2 (v3.1.1).The analysis of a public single-cell RNA-Seq dataset (Jerby-Arnon et al. 2018, Cell 175:984-997) ofmelanoma patients revealed that HPGDS expression is exclusively restricted to the TAM compartment,and is not expressed in the tumor stroma. This finding was further confirmed by analyzing an in-house single-cell RNA-Seq dataset where we found that HPGDS was highly expressed in macrophages but also in melanophages and mast cells (Figure 1A). Given the limiting number of mast cells infiltrating the tumor and the higher expression of HPGDS in macrophages compared to melanophages (Figure 1B), we decided MaMa / HPGDS / 822 to focus our attention only on macrophages. Interestingly, the expression of HPGDS was restricted tothe pro-tumoral M2-like macrophages (Figure 1C) and negatively correlated with activated CD8+ T cells(Figure 1D). Our findings were further corroborated by immunohistochemistry analysis on primary tumor as well as lymph nodes and liver metastases of melanoma patients, where a selective co-localization of HPGDS with TAMs can be appreciated (Figure 1E). Altogether, these observations pointed HPGDS as a potential marker to identify and thus target the pro- tumoral M2-like macrophages.EXAMPLE 2. Hpgds inhibition re-educates tumor-associated macrophages (TAMs) toward an M1-likephenotype Among all the cells of the immune system, we found that in orthotopic YUMM 1.7 melanoma Hpgds was almost exclusively expressed in TAMs, as assessed by measuring the transcript of Hpgds in different celltypes sorted from the tumor micro-environment (TME) (Figure 2A). According to Mary et al. 2022(Cancer Immunology Research 10:900-916), Hpgds is expressed on T follicular helper (Tfh) cells but noton other CD4+ T cell subsets. We confirmed the expression of Hpgds in this subset but its expression onlymph nodes was 80-fold lower than the expression detected on macrophages. In addition, no expressionof Hpgds on intratumoral CD4+T cells was detected. Then, we confirmed the selective colocalization of Hpgds with TAMs by immunofluorescence (Figure 2B).In line with this, Hpgds expression was nearly absent in in vitro M1-polarized BMDMs but very high inM2-like BMDMs (Figure 2C); HPGDS protein could not be detected in other tumor compartments ortissue macrophages from healthy organs. Strikingly, the same expression level of Hpgds observed inboth, sorted TAMs and M2-like macrophages was suggestive of a pro-tumoral role of Hpgds-expressingmacrophages. In contrast to YUMM1.7 melanoma, Hpgds expression in B16 melanoma was predominantin malignant cells and alveolar cells 1, with further scattered expression in NK cells, B cells, and monocytes / macrophages (Figure 7); when checking several tumor slides by immunohistochemistry noco-localization of HPGDS with TAMs could be observed (whereas such co-localization was observed inother tumors indicating that the HPGDS antibody did work).We then inquired about the biological role of Hpgds in macrophages. Thus, when characterizing Hpgds- silenced macrophages, we observed that its deletion in M0 or M2-like macrophages, strongly affects the expression of main M1 and M2 macrophage polarization markers, by re-educating macrophages towardsan M1-like phenotype (Figure 2D and 2N).The same was true in human monocyte-derived macrophages (hMDMs) where M2-like polarization(stimulation with IL-4) resulted in a higher expression of HPGDS compared to M1-like hMDMs(stimulated with LPS and IFNy) (Figure 2E). Supporting the murine data, HPGDS-silencing in both M0 and MaMa / HPGDS / 822 M2-like macrophages, skews their pro-tumoral, anti-inflammatory phenotype towards an anti-tumoral, immunostimulatory M1-like phenotype (Figure 2F and 2O).In further elucidating the functional role of Hpgds, we measured the abundance of Prostaglandin D2(PGD2) and we confirmed a reduction of this lipid mediator upon Hpgds inhibition (Figure 2G). As expected, the lipidomic analysis did not reveal any modification of other pro-tumoral lipid and lipid mediators, like Arachidonic Acid (AA) and Prostaglandin E2 (Figure 2P). However, the decreased levels of PGD2and its downstream active mediators was associated with a statistically significant increase of some pro-inflammatory mediators, like Thromboxane B2(Figure 2 P). Considering that PGD2can be synthetized by the action of two enzymes, Lpgds and Hpgds and only thislatter is expressed in macrophages, while Lpgds is predominantly expressed in endothelial cells (Figure2Q), we hypothesized that the decrease of PGD2 is a determinant factor to induce a pro-tumoral phenotype of these cells. Thus, we assessed macrophage polarization upon exposure to 1 µM of PGD2.Flow cytometric analysis revealed that PGD2 affects their polarization by promoting an anti-inflammatoryM2-like phenotype (Figure 2H). Consistent with the notion that macrophages can define blood vessel’s structure and function, we conducted a 3D spheroid sprouting assay in a type I collagen gel by co- culturing Hpgds-silenced macrophages with HUVECs. In these conditions we demonstrated that the silencing for Hpgds decreased the number and the length of sprouts formed by HUVECs (Figure 2I-K). Of note, we found that PGD2 treatment enhanced the expression in HUVECs of key regulators ofangiogenesis and lymphangiogenesis (i.e., VEGFA and VEGFC) in a time-dependent manner (Figure 2L),pointing at the Hpgds-PGD2 signaling as key driving force for tumor angiogenesis. In line with this, the pre-treatment of HUVECs with PGD2for 48 hr strongly increase their migratory capacity towards macrophages (Figure 2M). Together, these data suggest that Hpgds represents an anti-inflammatory macrophage marker and its targeting can have a strong impact on the tumor progression by engaging the immune-system and impeding angiogenesis.EXAMPLE 3. Hpgds deletion in tumor-associated macrophages (TAMs) inhibits tumor progression andreshapes the tumor micro-environment (TME)To investigate the functional role of Hpgds in TAMs, Hpgds expression was selectively deleted in thehematopoietic cell lineage of mice. Inducible macrophage-specific Hpgds KO mice were generated byintercrossing the tamoxifen-inducible Csf1r:Cre-ERT (a kind gift of J. W. Pollard from the University ofEdinburgh, Scotland) with LoxP-STOP-LoxP Cas9 (LSL-CRISPR / Cas9) mice (B6J.129(B6N)- Gt(ROSA)26Sortm1(CAG-cas9*,-EGFP)Fezh / J). hematopoietic / progenitor cells of these mice (lineage negativeHSCs, Lin-HSCs) were transduced with a validated gRNA against Hpgds or with non-targeting control MaMa / HPGDS / 822gRNA. Lethally irradiated wild-type (WT) mice were reconstituted with either of the two transducedhematopoietic / progenitor cells (Lin-HSCs), thus generating inducible Hpgds knockout (KO) WT andWT WT chimeras, respectively. Four weeks after the generation of the chimera, the immunereconstitution was confirmed and mice were treated with tamoxifen for five days. Hpgds genetic ablationwas confirmed at the RNA level, by differentiating in vitro HSC into macrophages and in vivo at theprotein level (Figure S3A). YUMM 1.7 melanoma cancer cells were intradermally injected in both WT ^WT and Hpgds KO WT mice 5 to 6 weeks after immune reconstitution.Hpgds deletion in the macrophage compartment led to a significant reduction in the tumor growth andtumor weight (Figure 3A). Consistent with our in vitro observation that Hpgds inhibition promotes aninflammatory phenotype in macrophages, the TAM compartment of Hpgds KO melanoma-bearing mice was strongly affected: although Hpgds knockout did not influence overall TAM infiltration (Figure3B), tumors in Hpgds KO WT chimera mice displayed more anti-tumoral macrophages, defined aspositive for MHC-II, CD11c and CD86 (Figure 3C) and less pro-tumoral M2-like macrophages, expressinglower level of MHC-II and positive for CD206 and CD204 (Figure 3D), suggesting that Hpgds is crucial fordetermining their differentiation state into M2 macrophages. By histological analysis we confirmed the pro-inflammatory phenotype of macrophages, characterized by more anti-tumoral M1-like macrophages, defined as positive for both F4 / 80 and CD80 and less pro-tumoral M2-like macrophages, defined as positive for both F4 / 80 and CD206 (Figure 3E). In addition, flow cytometry analysis of theimmune landscape revealed that tumors in Hpgds KO WT chimera mice displayed a slight increase inCD8+T cell infiltration (Figure 3F) with augmented secretion of Interferon γ (IFNγ) and granzyme B (GZMB) (Figure 3G). By histological analysis we could consistently observe an increase in CD8+T cellinfiltration at the tumor core (Figure 3H), suggesting a transition from an immune-excluded phenotype,characterized by an high number of CD8+T cells at the tumor border to the inflamed phenotype, in whichimmune cells are abundant and localized at the tumor core (Galluzi et al. 2018, Sci Transl Med10:eaat7807). These in vivo evidences were further validated using a more conventional approach, where the specificity of the KO was assessed by checking the expression of Hpgds (Figure 3I). Thus, by intercrossing Hpgds floxed mice with CD64:Cre mice we generated a murine model where Hpgds is specifically depleted in macrophages (CD64-Cre;HpgdsL / L; Hpgds-KO, HpgdsΔMΦor HpgdsΔMΦin short). When YUMM 1.7 melanoma cancer cells where intradermally injected in the Hpgds-KO mice and in the littermatecontrols (CD64-Cre; Hpgds+ / + or Hpgdswt / wt; Ctrl in short) the antitumoral effect of Hpgds was even morepronounced, with a reduction in tumor growth of almost 80% and tumor weight (Figures 3J). The reduced tumor size was associated with a pro-inflammatory phenotype in macrophages, with an increased number of M1-like macrophages expressing MHC-II, CD11c and CD86 and lower number of M2-like MaMa / HPGDS / 822 macrophages, expressing CD206 and CD204 (Figures 3K-O). The results obtained by flow cytometry wereconfirmed by histological analysis. In addition, as in the Hpgds KO WT model, the number of CD8+ Tcells (Figure 3O) and their activation status (Figure 3P) was augmented in Hpgds-KO tumors. Moving to the vessel compartment we found that tumor blood vessel perimeter as well as pericyte coverage, perfusion vessels and hypoxia (parameters linked to cancer cell intravasation into the bloodstream) were strongly affected by Hpgds-KO, with an overt functional and structural improvement which usuallycorrelates with a better disease outcome in patients (Mazzone et al. 2009, Cell 136:839-851) (Figures3Q). Finally, when checking the interstitial fluid we confirmed that the depletion of Hpgds in macrophages resulted in reduced levels of PGD2(Figure 3R) while other bio-active lipid mediators, like AA and PGE2were not affected by its inhibition (Figure 3R). This data where further confirmed by measuring the intratumoral level of PGD2 of Hpgds-KO tumors compared to the Ctrl tumors (Figure 3S). Hence, to further investigate the effect of a change in PGD2 released by macrophages, firstly we proved that YUMM 1.7 were migrating towards a gradient of PGD2, then we performed a co-culture of Hpgds- KO BMDMs with YUMM 1.7-melanoma cancer cells. Interestingly, cancer cell migration towards BMDMs Hpgds-KO was lower than towards Hpgds-WT (Figure 3T). Thus, tumor blood vessel density, perimeter, size, pericyte coverage, vessel perfusion, and tumor hypoxia were strongly affected by Hpgds deletion in TAMs, resulting in fewer vessels but with overt functional and structural improvements. We have shown before that increased vessel coverage and reduced tumor hypoxia prevent cancer cell dissemination from the primary tumor to distant organs (Mazzone et al.2009, Cell 136:839-851). Consistently, cancer cell intravasation into the bloodstream andlodging to the lungs in tumor-bearing HpgdsΔMø mice was lower than in controls (Figure 3U).All these data indicate that the metabolic editing of the TME via inhibition of HPGDS reshapes the immunosuppressive TAMs and boosts an anti-tumor immune response. The chimeric macrophage model as used herein plausibly supports use of adoptive transfer of macrophages in which HPDGDS expression is knocked-out or inhibited in the treatment of cancer.EXAMPLE 4. Targeting HPGDS in tumor-associated macrophages (TAMs) requires the presence of CD8+T cells to affect tumor progressionBased on the modified tumor micro-environment (TME) upon Hpgds depletion in macrophages, weproceeded with assessing the interaction of Hpgds-KO macrophages (HpgdsΔMø) with other tumor-infiltrating immune cells. To this end, we treated Ctrl and Hpgds-KO melanoma-bearing mice with an ^- CD8 depleting antibody. Of note, the depletion of CD8+T cells was checked in the blood before tumor injection and at the end stage of the experiment and in the tumor. Tumors in CD8-depleted mice in general showed bigger tumors and the anti-tumoral effect of Hpgds-KO in macrophages was completely MaMa / HPGDS / 822abolished upon CD8 depletion (Figure 4A-B), with the macrophages being re-educated toward an M1-like phenotype. Interestingly, the absence of tumor infiltrating CD8+T cells was not affecting the anti-tumoral role of TAMs in promoting vascular normalization (Figure 4C), and was not affecting metastasisinhibition by Hpgds-KO (Figure 4E). Taken together, these data argue that macrophages per se are ableto normalize the tumor vasculature which is not sufficient to inhibit tumor growth as the presence ofCD8+T cells is required to dampen tumor progression. Confirming the relevance CD8+T cells in the observed phenotype, flow cytometry analysis performed on Hpgds-KO and Ctrl BMDMs co-cultured with CD8+T cells revealed that the interaction between these two cells is sufficient to increase their activation (IFNγ+; TNF-^+) (Figure 4D). Finally, Ctrl and HpgdsΔMømice were orthotopically injected with YUMM 1.7 melanoma cancer cells and administered with αPD1 when the average tumor size of both groups was 150 mm3. Although Ctrl micedisplayed resistance to αPD1, Hpgds deletion in macrophages, sensitized tumors to αPD1 and inhibitedtumor relapse in HpgdsΔMø mice (Figure 4F and 4G).EXAMPLE 5. Pharmacologic inhibition of Hpgds inhibits tumor growth and re-educates macrophages towards an M1-like phenotype To translate the results obtained by using the genetic approach in a clinically relevant setting, we used the HPGDS-specific inhibitor HQL-79 [4-(Diphenylmethoxy)-1-(3-2H-tetrazol-5-yl)propyl]-piperidine; CASNo. 162641-16-9; InChI key TZQGXAHOROZEKN-UHFFFAOYSA-N] to pharmacologically target HPGDS inYUMM 1.7 melanoma bearing mice. Strikingly, by using a systemic approach we were able to recapitulate the anti-tumor phenotype induced by genetic deletion of Hpgds (Figure 5A). Indeed, the impairment intumor growth was driven by a re-education of tumor-associated macrophages (TAMs) toward an M1-like, pro-inflammatory, anti-angiogenic phenotype (Figure 5D-F) a robust infiltration of CD8+T cells with reinvigorated effector functions as assessed by the augmented secretion of effector cytokines such as IFNγ and GZMB, pointing to a shift toward an inflamed, anti-tumor phenotype. Similar results were obtained by taking advantage of a tumor cell line derived from an NrasQ61K; Ink4A- / -spontaneous melanoma model (Figure 5C).Like macrophage-specific Hpgds deletion, HQL-79 strongly affected the tumor vasculature by decreasingvessel density and size, and by improving morphologic and functional parameters such as pericyte coverage and perfusion, together with reduced hypoxia, cancer cell intravasation into the bloodstream(Figure 5G) and lung colonization (Figure 5G).The specificity of HQL-79 was proved by intercrossing Hpgds floxed mice with CD64:Cre-ERT2 mice (CD64-Cre-ERT2; HpgdsL / L; HpgdsΔMø-ERT2in short), where Hpgds was deleted in TAMs upon intraperitoneal injection of tamoxifen. The effect of either systemic inhibition or acute deletion in macrophages was MaMa / HPGDS / 822 comparable, and the inhibitor did not have any additional effect when administered to HpgdsΔMø-ERT2mice (Figure 5H).Comparable results were obtained with the use of a second HPGDS inhibitor, Cmpd1y (7-Cyclopropyl-N-((trans)-4-(2-hydroxypropan-2-yl)cyclohexyl)-1,8- naphthyridine-3-carboxamide; Cadilla et al. 2020,Bioorganic & Medical Chemistry 28:115791) showing a dose-response effect on tumor inhibition withthe highest efficacy at 3 mg / kg BID (i.e., 55% of tumor growth and weight inhibition versus vehicle)(Figure 5I). A less potent HPGDS inhibitor, TAS-205 (Aoyagi et al. 2020, Eur J Pharmacol 875:173030),also showed a robust therapeutic effect at 30 mg / kg BID (Figure 5J).Taken together, these data offer proof that pharmacological inhibition of HPGDS can sculpt TAMs away from their immunosuppressive state, providing a promising therapeutic option against melanoma. Furthermore, the involvement of HPGDS in cancer progression was studied in an high metastatic andlethal cancer indication. Hepatocellular carcinoma (HCC) was chosen. Firstly, we verified the selectiveexpression of HPGDS in macrophages (murine and human data). In the HCC model used, HPGDS wassystemically inhibited. Pharmacological inhibition of HPGDS affected the number and the size of both,macro and micronodules (Figure 5D-E) and led to an increased number of total macrophages (F4 / 80+)most likely due to more M1-like macrophages (Figure 5F). As in the melanoma tumor model, weobserved that HPGDS targeting resulted in a significantly higher infiltration of CD8+T cells, whereas the total number was not affected by the treatment. Taken together, these data offer a proof-of-concept that pharmacological inhibition of HPGDS can sculpt TAMs away from their immunosuppressive state and increase the fitness of CD8+T cells.The therapeutic effect of pharmacologic HPGDS inhibition was further tested in patient-derivedorganotypic tumor spheroids (PDOTs)(Jenkins et al.2018, Cancer Discovery 8:196-215). The treatmentwith 1µM HQL-79 for 72hr decreased the viability of the tumoroid (Figure 5K), and this decrease wasassociated with an accumulation of total and TNFα-producing CD8+T cells. HQL-79 did not affect total TAMs; however, these macrophages were re-educated towards an immunostimulatory phenotype.EXAMPLE 6. HPGDS systemic inhibition improves efficacy of immune checkpoint blockersDespite the strong anti-tumor effect mediated by the inhibition of HPGDS, we wondered if HPGDStargeting can enhance the response to immunotherapy. Thus, we referred back to human datasets andwe investigated the expression of HPGDS in immunotherapy treated patients. Strikingly, we found that HPGDS expression remains high in TAMs from non-responding patients, whereas it is “turned-off” in those patients that are responsive to ^-PD-1 therapy (Figure 6A).Our in vitro findings show that the inhibition of HPGDS induces Pdcd1 (gene encoding for PD-1) up-regulation in BMDMs. MaMa / HPGDS / 822 Of note, when treating YUMM 1.7 melanoma-bearing mice either with HPGDS pharmacological inhibitor alone or in concert with ^-PD-1, the effect of HPGDS inhibition in combination with ^-PD-1 administration could not be analyzed due to total regression of the tumors. We then took advantage ofa genetically engineered mouse (GEM) metastatic melanoma model (Dankort et al. 2009, Nat Genet41:544-552) carrying the most common mutations identified in human melanomas, BrafV600EPten- / -. Incontrast to the orthotopic YUMM 1.7 model, HPGDS targeting did not affect tumor progression (Figure 6B) albeit macrophages were re-educated towards an M1-like phenotype (Figure 6C). Flow cytometry analysis revealed no differences in the number of CD8+T cells (Figure 6D), but augmented PD1 expression (Figure 6E). This data suggested that although the total number of CD8+T cells did not change, thesecells were better suited to induce immunotherapy-response. Based on these observations, wehypothesized that, in this model, the mechanism of HPGDS-resistance is mediated by PD-1 up-regulation.Accordingly, the monotherapy (i.e., HQL-79 or ^-PD-1 alone) was not sufficient to reduce the tumor,whereas their combination showed a persistent and synergic effect (Figure 6F). From a mechanistic point of view, the combination with ^-PD-1 treatment did not add anything to the effect on macrophages,nevertheless, to affect tumor progression it requires the infiltration of CD8+ T cells (Figure 6G). Based onthese data we speculated that HPGDS systemic inhibition sensitizes tumors to immunotherapy, probablyby up-regulating PD-1 expression on CD8+T cells and thus promoting immunotherapy response. Congruently, we observed PD1 upregulation on CD8+T cells upon co-culture with Hpgds-KO BMDMs. Lastly, we extended our findings to one of the most lethally and aggressive tumor types, like pancreatic ductal adenocarcinoma (PDAC). Thus, we investigated the expression of HPGDS in PDAC. Consistent with the pro-tumoral role of HPGDS, its expression was high in the tumor tissue compared to the adjacent healthy tissue. We then confirmed the co-localization of HPGDS with macrophages in both, mouse and human tumors. To confirm the relevance of HPGDS in pancreatic tumors, we systemically inhibited HPGDS in orthotopically injected KPC FC1245. Like in the GEM model of melanoma, also here CD8+T cells are excluded (Scolaro et al. 2024, Nat Cancer 5:1206-1226). No differences in body weight were observed. Congruently, HPGDS systemic inhibition slightly decreased tumor weight while aPD1 did not have any effect. However, their combination was greatly effective (Figure 6H). Overall, these data show that inhibition of HPGDS in combination with ^-PD-1 reduces tumor growth, abates immunosuppression and can pave the way toward a possible therapeutic strategy to overcome resistance to immunotherapy. MaMa / HPGDS / 822 EXAMPLE 7. 7.1. Animal strains All experimental animal procedures were approved by the Institutional Animal Care and Research Advisory Committee of the KU Leuven (P226 / 2017 and P012 / 2022). Mice were maintained underpathogen-free and temperature- and humidity-controlled conditions with a 12-h light / 12-h dark cycleand received normal chow (sniff, R / M-H). Animals were removed from the study and killed if any signs of pain and distress were detected or if the tumor volume reached 1000mm3. The maximal tumor size was not exceeded in all reported studies. Macrophage-specific Hpgds KO mice were generated by intercrossing the tamoxifen-inducible Csf1r:Cre-ERT (a kind gift of J. W. Pollard from the University of Edinburgh, Scotland) with LoxP-STOP-LoxP Cas9mice (B6J.129(B6N)- Gt(ROSA) 26Sortm1(CAG-cas9*,-EGFP)Fezh / J) (Shang et al.2020, Nature 587:626-631), purchased from Jackson Laboratory.BrafV600E Pten- / - mice (a kind gift of J-C. Marine from VIB-Center of Cancer Biology, Leuven, Belgium) weregenerated by intercrossing BrafCA, Tyr::Cre-ERT2mice with Ptenlox4-5mice. The Cre-mediated conversion of BrafCAto BrafVEand the deletion of exons 4 and 5 was obtained by topical administration of 2 mg / ml (5mM) of 4-hydroxytamoxifen (4-HT) on the back skin of adult mice.The mouse line C57BL / 6N-Hpgds / Tcp was made as part of the KOMP2-DTCC project from KOMP ES cells(Bradley et al. 2012, Mamm Genome 23:580-586) at The Centre for Phenogenomics. It was obtainedfrom the Canadian Mouse Mutant Repository. The NEO cassette was deleted in vivo by using FLP- mediated recombination. The final transgenic line carries 2 LoxP-sites in each Hpgds allele. Finally, we generated Fcγr1.Cre x Hpgdslox / loxmice in a C57BL / 6N background by intercrossing Hpgdslox / loxmice with the macrophage specific Fcγr1.Cre delete mouse line.Fcγr1-Cre mice were a gift from Bernard Malissen (French National Centre for Scientific Research, CNRS).We thank the Wellcome Trust Sanger Institute Mouse Genetics Project (Sanger MGP) and its funders for providing the mutant mouse line C57BL / 6NTac-Fcγr1tm(EGFP / Cre / ERT2)Wtsi / WtsiH, and the European Mouse Mutant Archive (www.infrafrontier.eu; Repository number EM: 11125) partner at the Mary Lyon Centre at MRC Harwell from which the mouse line was received. Thus, we intercrossed Fcγr1-Cre-ERT2 with Hpgdslox / loxmice to generate the conditional Hpgds-KO mouse. Macrophage-specific Ptgdr and Ptgdr2 KO were generated by intercrossing Hpgdslox / lox-Fcγr1.Cre micewith LoxP-STOP-LoxP Cas9 mice (B6J.129(B6N)- Gt(ROSA) 26Sortm1(CAG-cas9*,-EGFP)Fezh / J mice.LoxP-STOP-LoxP Cas9 mice (B6J.129(B6N)- Gt(ROSA) 26Sortm1(CAG-cas9*,-EGFP)Fezh / J mice wereintercrossed with NKp46 mice (Proc Natl Acad Sci USA 108:18324-18329) to generate NK-specific Ptgdrand Ptgdr2-KO mice. MaMa / HPGDS / 822 All mice used were females between 7-10 weeks old. Wild type C57BL / 6N mice were obtained from the KU Leuven breeding facility. 7.2. Cell lines The melanoma YUMM 1.7 cell line was a kind gift from Prof. R. Marais (Manchester, UK) and cultured in DMEM / F-12 medium (Gibco) supplemented with 10% FBS, 1% (v / v) Pen / Strep (Gibco) 2 mM glutamine (Gibco), 0.1 mM nonessential amino acid (NEAA, Gibco). The Nras-driven melanoma cell line (kindly provided by Prof. J-C. Marine, VIB-CCB KU Leuven) was generated by isolation of Tyr::Cre-ER(T2); Tyr::Ink4a- / -;R62R Confetti tumors and cultured in DMEM / F- 12 medium (Gibco) supplemented with 10% FBS, 1% (v / v) Pen / Strep (Gibco) and 2 mM glutamine (Gibco). The cells were incubated at 37^C in a 5% CO2 humidified atmosphere and subcultured approximately every three days to maintain a log growth phase. The KPC pancreatic cell line (FC1245) was a kind gift from Prof. D. Tuveson and was derived from spontaneous tumors arising KPC (KrasLSL.G12D / +; p53R172H / +; Pdx: CreTg / +) pancreatic cancer mouse model. KPC cells were cultured in DMEM medium (Gibco) supplemented with 10% FBS, 1% (v / v) Pen / Strep (Gibco), 1mM sodium pyruvate (Gibco). All the cancer cell lines used were authenticated by Idexx Bioresearch. 7.3. Cell Isolation and Culture 7.3.1. Murine Bone Marrow-Derived Macrophages (BMDMs)Murine BMDMs were derived from bone marrow precursors as described before (Casazza et al. 2013,Cancer Cell 24:695-709; Bieniasz-Krzywiec et al.2019, Cell Metab 30:917-936). Briefly, bone marrow cells were cultured in a 10 cm Petri dish (non-tissue culture treated, bacterial grade) in a volume of 6 ml of DMEM supplemented with 20% FBS and 30% L929-conditioned medium. After 3 days of culture, an additional 3 ml of differentiation medium was added. At day 7, macrophages were detached with ice cold PBS and characterized by FACS, using the pan-macrophage marker F4 / 80. For the in vitro M1 or M2 polarization, BMDMs were stimulated for additional 48h with 20 ng / ml IFN-γ + 100 ng / ml LPS or 10ng / ml IL-4, respectively. 7.3.2. CD8 isolation and activation Murine naïve T cells were isolated from the spleen by processing the cells through a 40-µm pore cell strainer in sterile PBS and cells were centrifuged for 10 min at 300x g. Red blood cell lysis buffer (Sigma- Aldrich) was used in order to lysis red blood cells. CD8+T cells were isolated by using MagniSort Mouse CD8+T Cell Negative Selection Kit (Thermo Fisher Scientific), according to the manufacturer’s instructions. CD8+T cells were cultured in T cell medium (RPMI supplemented with 10% FBS, 1% P / S, 1% MEM non- essential amino acids NEAA (Gibco), 25 µmol / L β-mercaptoethanol, and 1 mmol / L sodium pyruvate MaMa / HPGDS / 822(Gibco)) at 37°C in a humidified atmosphere containing 5% CO2. If needed, T cells were activated for 3days with CD3 / CD28 Dynabeads (Thermo Fisher Scientific) at a 1:1 bead-to-cell ratio and 30 U / ml rIL-2(PeproTech).3 days after the activation, the beads were magnetically removed and activated CD8+T cells were further expanded for maximum 3 days in the presence of rIL-2. 7.3.3. NK cells isolation Murine NK cells were isolated from the spleen by processing the cells through a 40-µm pore cell strainer in sterile PBS and cells were centrifuged for 10 min at 300x g. Red blood cell lysis buffer (Sigma-Aldrich)was used in order to lyse red blood cells. Cells were re-suspended in FACS buffer and incubated form 15minutes with BD Fc Block purified Rat Anti-Mouse CD16 / CD32 mAb (BD Pharmingen) and stained with the following antibodies for 30 minutes at 4^C protected from light: viability dye (eF506), anti-CD45(clone 30-F11), anti-CD11b (clone M1 / 70), anti-F4 / 80 (clone BM8), anti-CD8 (clone 53-6.7), anti-CD161 / NK1.1 (clone PK136), anti-CD335 / NKp46 (clone 29A1.4). Cells were then washed and re- suspended in cold FACS buffer before flow sorting by FACS Aria (BD Biosciences). FMO (Fluorescence Minus One) control was used in order to ensure proper gating of positive population. Subsequently, NK cells were expanded in T cell medium (RPMI supplemented with 10% FBS, 1% P / S, 1% MEM non-essential amino acids NEAA (Gibco), 25 µmol / L β-mercaptoethanol, and 1 mmol / L sodium pyruvate (Gibco)) in the presence of rIL-2. 7.3.4. Human Monocyte-Derived Macrophages (hMDMs) Human monocytes were obtained from healthy donor buffy coats and isolated with CD14-conjugatedMicroBeads (Miltenyi Biotec) as described before (Bieniasz-Krzywiec et al.2019, Cell Metab 30:917-936).Briefly, monocytes were cultured in a 6-well plates (1x106cells / well in 2 ml media) in RPMI 10 % FBS, 2 mM L-Glutamine, 1% P / S and 25 ng / ml recombinant human M-CSF for five days. The third day of the differentiation, cytokines were refreshed. At day 6, macrophages were detached with ice cold PBS orpolarized for additional 48h towards an M1 or M2 phenotype with 10 ng / ml IFN-γ + 100 ng / ml LPS or 20ng / ml IL-4, respectively. 7.3.5. Human Umbilical Endothelial Cells (HUVECs) HUVECs were freshly isolated from umbilical cords obtained from multiple donors (with approval from the Ethics Committee Research UZ / KU Leuven and informed consent obtained from all subjects) aspreviously described (Bieniasz-Krzywiec et al.2019, Cell Metab 30:917-936; Schoors et al.2015, Nature520: 192-197) and regularly tested for mycoplasma. They were maintained in M199 medium (Invitrogen)supplemented with 20% FBS, 2nM glutamine, 100 U / mL penicillin, 100 µg / mL streptomycin, 0.15% heparin and 20 µg / mL ECGS (Sigma-Aldrich).0.1% pork gelatin (Sigma-Aldrich) was used to stimulate the adhesion of HUVECs to the flask bottom. MaMa / HPGDS / 822 7.4. Tumor models 1x106YUMM1.7 or 1x106Nras-driven melanoma cell lines, genetically engineered by lentiviral transduction to express CD90.1, were injected intradermally in the right flank of the mouse in a finalsuspension of 50 μl PBS. Tumor volumes were measured three times a week with a calliper andcalculated using the formula: V = ^ x [d2 x D] / 6, where d is the minor tumor axis and D is the majortumor axis. At the indicated time points, mice were randomized and treated intraperitoneally (ip) with 5 mg / kg α-CD8 (BioXcell) or control IgG from rat serum. For the pharmacological inhibition of Hpgds, mice were treated by oral gavage with HQL-79 30 mg / kg BID or control vehicle (methylcellulose). Treatment started when the average tumor reached 100 mm3. For the hepatocellular carcinoma spontaneous model, mice were hydrodynamically cotransfected with 0.1 ug of PB_h-RasG12V and PB_c-Myc, in conjunction with a plasmid encoding a hyperactive PBtransposase (Serra et al.2022, Cell Mol Gastroenterol Hepatol 14:609-624; Tipanee et al.2020, Mol TherNucleic Acids 19:1309-1329; Di Matteo et al. 2014, Mol Ther 22:1614-1624). For the pharmacological inhibition of Hpgds, mice were treated by oral gavage with HQL-7930 mg / kg BID or control vehicle (methylcellulose). Treatment started 9 weeks after hydrodynamic injection. Mice were weighted at least three times per week. Mice showing symptoms of illness, losing 20% of initial body weight, displaying peritoneal leakage or ulcerated tumors were sacrificed and excluded from the experiments. At the end stage (13 weeks after hydrodynamic injection), nodules were counted as measured by using a calliper. Moreover, one lobe was collected for histological examination. For the genetically engineered mouse metastatic melanoma model (BrafV600EPten- / -), topical administration with 2 mg / ml (5mM) of 4-hydroxytamoxifen (4-HT) on the back skin of adult mice was performed.4 weeks after tumor induction, mice were randomized and treated intraperitoneally with 10 mg / kg α-PD-1 (BioXcell), control IgG from rat serum. For the pharmacological inhibition of HPGDS, mice were treated for 13 days by oral gavage with HQL-7930 mg / kg BID or control vehicle (methylcellulose). 7.5. Bone marrow transplantationFor the generation of Hpgds WT mice, the stop-floxed Cas9 knockin line (Platt et al. 2014, Cell159:440-455) was intercrossed with Csf1r:Cre-ERT mice allowing the inducible expression of the Cas9nuclease in monocytes and macrophages only (donor mice). Seven-to-eight-week-old recipient micewere lethally irradiated with a dose of 9.2 Gy using the Small Animal Radiation Research Platform (SARRP, XSTRAHL). After cervical dislocation, femur, tibia and humerus were collected from donor mice of theappropriate genotype. Bone marrow (BM) was obtained by flushing the bones with a syringe filled withDMEM supplemented with 10% FBS. The cells were subsequently filtered two times by using a 40-µM- pore-sized mesh and centrifuged for 10 minutes at 300x g. BM cells were counted and resuspended 1x108cells / ml. The EasySepTMMouse Hematopoietic Progenitor Cell Isolation Kit (19856, STEMCELL MaMa / HPGDS / 822 Technologies) was used to isolate lineage-negative hematopoietic stem cells (Lin-HSCs) according to themanufacturer’s instructions. Cells were stimulated for 4h in StemSpanTM serum-free medium (09650,STEMCELL Technologies) with 20 ng / ml IL-3, 100 ng / ml SCF, 100 ng / ml TPO and 100 ng / ml FLT-3L andthen transduced with a specific gRNA of interest (targeting or, as control, non-targeting). A multiplicityof infection reaching approximately 30% of transduction was used. After a double spin filtration, cells were counted and 1x106cells were injected intravenously (iv) via tail vein in the irradiated recipient mice.Tumor experiments were initiated 5 to 6 weeks after immune reconstitution. Deletion of Hpgdsexpression in macrophages was induced by intraperitoneal injections of tamoxifen (Sigma-Aldrich,T5648) (1mg / mouse / day) for 5 consecutive days. Red and white blood cell count was determined using hematocytometer and flow cytometry on peripheral blood collected in heparin with capillary pipettes by retro-orbital bleeding. Tumor experiments were initiated 5 to 6 weeks after immune reconstitution. 7.6. Tissue dissociation YUMM 1.7 and Nras-driven melanoma-bearing mice were sacrificed by cervical dislocation. Tumors were harvested and minced in ^MEM medium (Lonza) supplemented with 5% FBS, 1% Pen / Strep, 50 μM β- mercaptoethanol (Gibco), 5 U / ml DNase I (Qiagen), 0.85 mg / ml Collagenase V (Collagenase from Clostridium histolyticum, Sigma-Aldrich), 1.25 mg / ml Collagenase D (Collagenase from Clostridium histolyticum, Roche) and 1 mg / ml Dispase II (Gibco) and digested for 30 minutes at 37°C. Digested tissues were filtered using first a 70-µm and then a 40-µm pore mesh strainers. BrafV600EPten- / -mice were sacrificed by cervical dislocation. Spontaneous tumors were harvested and minced in RPMI supplemented with 5% FBS, 300 μg / ml Liberase (Sigma Aldrich) and 1 μg / ml DNase I (Qiagen) and digested for 45 minutes at 37°C. The single cell suspension was then passed through a 40 µm strainer and red blood cells were lysed by using a Hybri-Max solution (Sigma Aldrich). 7.7. Tumor-conditioned media (TCM) YUMM 1.7 tumor explanted from WT mice was minced in 12 ml DMEM / F-12 medium, supplemented with 1% Pen / Strep and incubated at 37°C for 72 hours. After that, the medium was filtered, and the cell- free supernatant was supplemented with 20mM HEPES and 2mM of L-glutamine and stored at −20°C. 7.8. Tumor interstitial fluid (TIF)YUMM 1.7 tumor explanted from Hpgds WT and KO mice were cut in small pieces which were insertedin collection tubes (2 ml eppendorfs with 5 holes at the bottom in a 15 ml falcon tube).20 to 40 μl of 9g / l NaCl pH 7.4 was added on top of the tumor samples prior to a 10 min centrifugation at 110x g at 4°C.The interstitial fluid was collected in new vials and further used to assess lipid metabolites and mediators by using the liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS / MS) on a Nexera X2 UHPLC system (Shimadzu). MaMa / HPGDS / 822 7.9. YUMM 1.7 migration assay In the cancer migration assays, 8x104YUMM 1.7 melanoma cancer cells were seeded on 8 μmpolycarbonate membranes (Transwell; Costar). The bottom chamber contained DMEM without PGD2 orwith 10 nM, 100 nM, 1 μM or 10 µM PGD2, or alternatively 2x105BMDMs Hpgds-WT or Hpgds-KO. For the co-culture with macrophages, the bottom chamber contained 2x105IL-4 polarized macrophages (Ctrlor Hpgds-KO).12hr before starting the assay, YUMM 1.7 and BMDMs were cultured in DMEM F-12 with2% FBS, 1% P / S and 1% L-Glut. Subsequently, cells were seeded and incubated for 12hr. The non- migrated cells were removed from the top of each membrane by using a cotton stick. The migrated cellswere fixed in 4% PFA, washed in PBS, stained with crystal violet (2.5 g / l), and mounted on glass slideswith ProLong Gold mounting medium without DAPI. Images were acquired with Olympus BX41 or LeicaDMI6000 microscope and analyzed using the CellSense imaging software.7.10. BMDM electroporationSilencing of Hpgds, Ptgdr and Ptgdr2 was achieved by electroporation with specific siRNAs. Briefly, 8x106BMDMs were resuspended in 500 μl of Opti-MEM and electroporated (250V, 950 mF, ∞ Ω) with 100pmol of the targeting or control siRNA of interest. After electroporation, medium was replaced withDMEM supplemented with 10% FBS, 1% Pen / Strep and 2mM Glutamine (Gibco). Upon 48h of incubation at 37°C in a 5% CO2humidified atmosphere, qPCR and flow cytometric analysis were performed. 7.11. hMDMs transfectionSilencing of HPGDS was achieved by transfecting hMDMs with specific siRNAs (commercially available).Briefly, 1x106hMDMs were transfected by using LipofectamineTMRNAiMAX Transfection Reagent(Thermo Fisher Scientific).10 pmol of of the targering or control siRNA of interestwere resuspended in100 μL of Opti-MEM supplemented with 2 μL of Lipofectamine and incubated for 20 minutes at RT.6hr after lipofection, medium was replaced with RPMI supplemented with 10% FBS, 1% Pen / Strep and 2 mM Glutamine. Upon 48h of incubation at 37°C in a 5% CO2humidified atmosphere, qPCR and flow cytometric analysis were performed. 7.12. BMDMs in vitro For the in vitro polarization assays, 1x106BMDMs were seeded 24h prior to the addition of 1^M of PGD2. After 48h of stimulation, the polarization was assessed by flow cytometry. To differentiate BMDMs towards TAMs-like cells, 4x106BMDMs were seeded in 6-well plates in DMEM supplemented with 10% FBS, 1% P / S and 20% TCM for 12h at 37 °C in a 5% CO2 humidified atmosphere, as previously described. 7.13. Sprouting assay Hybrid multicellular microspheres were generated by mixing HUVECS and BMDMs (wild-type or silencedfor Hpgds) in a 1:1 ratio and incubated overnight in hanging drops in EGM-2 medium supplemented with20% methylcellulose 4000 cP (Sigma-Aldrich). After harvesting the spheroids, they were embedded in MaMa / HPGDS / 822Collagen I gel as described (Heiss et al.2015, FASEB J 29:3076-3084) and maintained at 37°C for 18 hoursto induce sprouting. Cultures were then fixed with 4% PFA at room temperature. Images were taken with a Leica DMI6000 microscope. The CellSense imaging software was used to analyze the number ofsprouts per spheroid and the total sprout length (represented by the cumulative length of primarysprouts and branches per spheroid). 7.14. HUVECs in vitro 100.000 HUVECs were seeded 24h prior to the addition of 1^M of PGD2. After 12-24-48hr of stimulationwith PGD2, the expression of VEGFA and VEGFC was assessed by qPCR.7.15. HUVEC migration assay 100.000 HUVECs were pre-treated for 48hr with PGD2or with DMSO and seeded for 12hr on 8 μm polycarbonate membranes (Transwell; Costar). The bottom chamber contained 200.000 BMDMs. The non-migrated cells were removed from the top of each membrane by using a cotton stick. The migratedcells were fixed in 4% PFA, washed in PBS, stained with crystal violet (2.5 g / l), and mounted on glassslides with ProLong Gold mounting medium without DAPI. Images were acquired with Olympus BX41 microscope and CellSense imaging software. 7.16. Gene expression analysis To assess gene expression, cells were washed in PBS, collected in RLT buffer (Qiagen) and stored at - 80°C. RNA was extracted with the RNeasy Minikit (Qiagen) according to the manufacturer’s instructions. Reverse transcription to cDNA was performed with the SuperScript III and SuperScript IV First Strand cDNA Synthesis System (Invitrogen) according to manufacturer’s protocol. cDNA, primer / probe mix andPowerUp SYBR Green Mix (Applied Biosystems) or TaqMan Fast Universal PCR Master Mix (AppliedBiosystems) were prepared in a volume of 20 µl or 10 µl, according to manufacturer’s instructions (Applied Biosystems) and pipetted into an optical 96-well Fast Thermal Cycling plate (AppliedBiosystems). Analysis was performed by using the QuantStudio 12K Flex Real-Time PCR System (AppliedBiosystems). Gene transcription was presented as number of gene mRNA copies relative to thehousekeeping gene. All reactions were run in duplicate. 7.17. Flow cytometry Cells were counted and blocked by using BD Fc Block purified Rat Anti-Mouse CD16 / CD32 mAb (BD Pharmingen). For the extracellular staining, cells were stained for 30 minutes on ice with the following antibodies: fixable viability dye (eF450 or eF506), anti-CD45 (clone 30-F11), anti-CD11b (clone M1 / 70), anti-F4 / 80 (BM8), anti-MHC-II (clone M5 / 114.15-12), anti-CD80 (clone B7-1), anti-CD86 (clone GL-1), anti-CD11c (clone N4 / 18), anti-CD206 (clone MR5D3), anti-CD204 (clone 7C9C20), anti-CD274 / PD-L1 (clone 10F.9G2), anti-CD8a (clone 53-6.7), anti-CD4 (clone RM4-5), anti-CD69 (clone H1.2F3), anti-CD279 / PD-1 MaMa / HPGDS / 822 (clone 29F.1A12), anti-CD335 / NKp46 (clone 29A1.4), anti-CD49b (clone DX5), anti-NK1.1 (clone PK136) from Cell Signaling, BD Bioscience, BioLegend, eBioscience and Miltenyi Biotec. For the intracellular measurements of tumor necrosis factor-alpha (TNF-α), interferon-γ (IFN-γ) and granzyme B (GZMB), single-cell suspensions were stimulated with phorbol 12-myristate 13- acetate / ionomycin cell stimulation cocktail (eBioscience) in presence of Brefeldin A (BioLegend) and Monensin (eBioscience) for 4h at 37°C in RPMI supplemented with 10% FBS and 1% Pen / Strep. Afterward, cells were stained for surface markers, followed by 30 min incubation in Fix / Perm(eBioscience) at 4°C. Cells were then washed with permeabilization buffer and stained overnight withthe following antibodies: anti-TNF-α (clone MP6-XT22), anti-IFN-γ (clone XMG1.2) and anti-GZMB (clone GB11). Cells were subsequently washed and resuspended in cold FACS buffer. FACS data were acquired by a FACS Fortessa (BD Biosciences). Fluorescence minus one (FMO) controls and unstained control were used to ensure proper gating of positive populations. Data were analyzed by using FlowJo (TreeStar). 7.18. Cell sorting 1x106YUMM1.7 CD90.1+were intradermally injected in the right flank of the mouse. Tumors were harvested for FACS as previously mentioned. After obtaining single cell suspension, CD45 enrichment was done by following manufacturer’s instructions (CD45 MicroBeads). Cells (CD45+and CD45-) were then incubated with Mouse BD Fc Block purified Rat-Anti-Mouse CD16 / CD32 mAb (BD Pharmingen) for 15 minutes at 4°C and stained with the following antibodies for 30 minutes at 4°C: fixable viability dye(eF450 or eF506), anti-CD45 (clone 30-F11), anti-CD11b (clone M1 / 70), anti-F4 / 80 (clone BM8), anti-TCR-β chain (clone H57-597), anti-CD8a (clone 53-6.7), anti-CD4 (clone RM4-5), anti-CD90.1 (clone OX-7),anti-CD90.2 (clone 53-2.1) anti-CD31 (clone MEC 13.3), anti-Ly6G (clone 1A8), anti-FcεR1α (clone MAR- 1), anti-CD117 (clone 2B8), anti-CD49b (clone DX5), anti-NKp46 (clone 29A1.4), anti-NK1.1 (clone PK136),anti-MHC-II (clone M5 / 114.15.2), anti-CD11c (clone N418), anti-CD279 / PD1, or anti-CXCR5. Cells werewashed and resuspended in cold FACS buffer before flow sorting. FMOs controls and unstained control were used to ensure proper gating of positive populations. Data were analyzed by FlowJo (TreeStar). 7.19. T-cell proliferation assay To assess T cell proliferation, activated CD8+T cells (at day 3 of stimulation) were counted and the 800 x 105cells were labeled with 3.5 ^mol / L Violet Cell Tracer (Thermo Fisher Scientific) at 37°C for 20 minutes. T cells were washed with FACS buffer and cultured for 48 hours the after stimulation. 7.20. Lipid extractionThe extraction protocol was adapted from an already described method (Dumlao et al. 2011, BiochimBiophys Acta – Mol Cell Biol Lipids 1811:724-736). Tissue samples were mixed with methanol containing100 picogram deuterated internal standards and 10 µL antioxidant mix (100 μM indomethacin, 0.2 mg / ml BHT, 100 μM trans-4-(-4-(3-adamantan-1-yl-ureido9-cyclohexyloxy)-benzoic acid (t-AUCB) in MaMa / HPGDS / 822 MeOH) and were homogenized using a Precellys system at 4°C. The homogenized samples were stored at -80°C for 30 minutes and then centrifuged at 16,000g for 10 minutes at 4°C. The supernatant wastransferred to a new tube and diluted with water to achieve a methanol percentage < 10%. Theremaining pellet was redissolved in TBS buffer for protein concentration determination (Pierce™ BCAProtein Assay, Thermo Fisher Scientific) or TE buffer for DNA concentration determination (Hoechst assay). Lipids were extracted using Strata™-X 33 µm Polymeric Reversed Phase extraction columns (Phenomenex, 8B-S100-ECH) as instructed by the manufacturer. Briefly, the columns were preconditioned with 3 mL methanol, followed by 3 mL water. The sample (containing < 10% methanol) was eluted dropwise, followed by a wash step with 3 mL of 10% methanol and elution with 100% methanol into a glass collection tube containing 6 µL of a 30% glycerol in methanol solution. Samples were evaporated in a vacuum centrifuge, redissolved in a 1:1 solution of water / methanol and transferred to an LC vial. 7.21. LC-MS / MS Lipid species were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS / MS) on a Nexera X2 UHPLC system (Shimadzu) coupled with a hybrid triple quadrupole / linear ion trap mass spectrometer (QTRAP 6500+ system; SCIEX). Chromatographic separation was performed on a Polar C18 column (2.6 μm, 3.0 x 100 mm; Phenomenex) maintained at 50°C, using mobile phase A [0.1% formic acid in water] and mobile phase B [0.1% formic acid in methanol]in the following gradient: (0-2 min: 45% B; 2-16.5 min: 45% B 80% B; 16.5-18.5 min: 98% B; 18.5-20.5min: 10% B) at a flow rate of 0.5 mL / min. The instrument parameters were as follows: Curtain Gas = 30 psi; Collision Gas = 8 a.u. (medium); IonSpray Voltage = 5200 V and −4,200 V; Temperature = 520°C; Ion Source Gas 1 = 50 psi; Ion Source Gas 2 = 70 psi. The endocannabinoids, LTC4, LTD4, LTD4, 2-AG, MTCR and PTCR compounds were detected in positive ion mode and all other compounds were detected innegative ion mode. MRM transitions were sourced from Murphy 2014 (Tandem Mass Spectrometry ofLipids (Robert C Murphy) 10.1039 / 9781782626350) and Stassburg et al. 2015 (Targeted Lipidomics of Oxylipins (Oxygenated Fatty Acids).10.13140 / RG.2.1.3943.9207). 7.22. PBMC isolation, MDM differentiation and polarization Buffy coat samples from healthy donors were obtained from the Red Cross-Flanders (institutional approval RKOV_19015). Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll density centrifugation (Axis-Shield, 1114545) and washed in PBS containing 1 mM EDTA. The ring at the interface was collected, washed with PBS and counted. Monocytes were isolated by using magnetic CD14-conjugated Microbeads (Miltenyi Biotec) and differentiated into human monocyte-derived macrophages(MDMs). Thus, monocytes were cultured in a 6-well plates (1x106cells / well in 2 ml media) in RPMI 10 % FBS, 2 mM L-Glutamine, 1% P / S and 25 ng / ml recombinant human M-CSF (PeproTech) for five days. The MaMa / HPGDS / 822 third day of the differentiation, cytokines were refreshed. The polarization towards the M1 or the M2- like phenotype was started at day 6. MDMs were polarized towards the M1-like phenotype by adding 10 ng / ml INF-γ (PeproTech) + 100 ng / ml LPS (Sigma-Aldrich) while, for the M2-like phenotype MDMs were polarized by adding 20 ng / ml IL-4 (PeproTech). After 48h polarization, M0 or M2-like macrophages weresilenced for HPGDS and the phenotype was checked by qPCR and flow cytometry. Thus, macrophageswere harvested, re-suspended in FACS buffer (PBS, FBS 2% and EDTA 2mM) and incubated for 15 min at 4°C with human Fc blocking (eBioscience). The following anti-human antibodies were used: anti-CD80(clone L307.4), anti-HLA-DR (clone LN3), anti-CD163 (clone GHI / 61), anti-CD206 (clone 19.2) and fixableviability dye (ThermoFisher, 65-0865-18). After staining, cells were washed, fixed and re-suspended in cold FACS buffer. Samples were analyzed using a LSRFortessa (BD Biosciences) flow cytometer. FMO controls were utilized in order to ensure proper gating of positive populations. 7.23. Histology and immunostainings Murine tumors were collected and fixed in 4% paraformaldehyde (PFA) overnight at 4°C, dehydrated and embedded in paraffin. Serial sections of 7-µm thickness were cut using a Microm HM360 Microtome. Human melanoma, hepatocellular carcinoma and pancreatic cancer samples were obtained as 7 µm thick paraffin-embedded slides. Paraffin slides were rehydrated to further proceed with antigen retrieval solution (Dako) for 20 minutes at 100°C. After 20 minutes of cooling down, the sections were washed with TBS and kept in methanol. If necessary, 0.3% H2O2 was added to methanol to inactivate endogenous peroxidases. The samples were washed and blocked with the appropriate serum (pre-immune donkey serum or pre-immune goat serum, Sigma-Aldrich) diluted 1:5 in Tris-NaCl-blocking buffer (TNB). Afterwards, the sections were incubated overnight with the following antibodies: rabbit anti-Hpgds (Cayman Chemical Company, 10004349), rat anti-F4 / 80 (AbD Serotec, MCA497 or Cell Signaling D2S9R), goat-anti-MMR / CD206 (R&D System AF2535), rabbit anti-CD80 (Abcam, ab64116), rabbit anti-mouse CD8 (Cell Signaling, 98941S), rabbit-anti mouse NKp46 (BD Pharmingen, 137601), goat anti-mouse CD105 / Endoglin (R&D System, AF1320), rabbit anti-^SMA-Cy3 (Sigma Aldrich, C6198), rabbit anti- hypoxyprobe (Hypoxyprobe kit, Chemicon), rabbit-anti FITC (AbD Serotec, 4510-7604), anti-human CD68 (Dako, M0876), anti-human HPGDS (R&D System, MAB6487). Next, Alexa 488, 568 or 647 conjugatedsecondary antibodies (Molecular Probes) or biotin-labeled antibodies (Jackson Immunoresearch) wereapplied. After biotin-labelled antibodies, TSA Cyanine 3, TSA Cyanine 5 or TSA Fluoresceine system amplification kits (Perkin Elmer, Life Sciences) were used according to the manufacturer’s instructions. The sections were then washed, stained for 30 min with Hoechst solution and mounted with ProLong Gold mounting medium without DAPI (Invitrogen). Imaging and microscopic analyses were performed with an Olympus BX41 microscope and CellSense imaging software. MaMa / HPGDS / 822 7.24. Hypoxia assessment and tumor perfusion For the detection of tumor hypoxia, tumors were collected 1h after intraperitoneal injection of 60 mg / kg pimonidazole hydrochloride into melanoma-bearing mice. To detect the formation of pimonidazole adducts, 7-^m sections were stained with Rabbit anti-hypoxyprobe monoclonal (Hypoxyprobe Kit, Chemicon) following the manufacturer’s instructions. To analyze vessel perfusion, tumors were collected 15 minutes after retro-orbital injection of 0.05 mg of FITC-conjugated lectin (Lycopersicon esculentum; Vector Laboratories, B-1175-1). 7.25. Statistics Data entry were performed in a blinded fashion. All statistical analyses were performed using GraphPad Prism software (Version 10.0.2). Statistical significance was calculated by two-tailed unpaired Student’s t-tests on two experimental conditions and one-way or two-way analysis of variance ANOVA when repeated measures were compared. All the results are shown as mean ± standard error of the mean (SEM). Statistics were indicated only when significant. Detection of mathematical outliers was performed using the Grubbs’ test in GraphPad. Sample sizes for all experiments were selected based on those reported in previous studies. Independent experiments were pooled and analyzed together whenever possible as detailed in figure legends. Animals were excluded if they died or had to be killed according to protocols approved by the animal experimental committees. 7.26. Meta-analysis To identify metabolic genes that are associated with the outcome of PD1 immunotherapy on human melanoma, we performed a meta-analysis on two publicly available bulk RNA-sequencing datasets ofhuman melanoma tumors responding or resistant to α-PD-1 immune checkpoint inhibitors (Hugo et al.2016, Cell 165:35-44; Riaz et al.2017, Cell 171:934-949). Briefly, raw reads were retrieved using the SRA toolkit (v2.8.0) and aligned to the human reference genome GRCh38.p13 using STAR (v2.7.3a) with default parameters. Next, featureCounts from the R (v3.6.2) package ‘Rsubread’ (v2.0.1) was used to assign mapped reads to genomic features. The resulting raw count matrices were further processedusing the BIOMEX browser-based software platform (v1.0.5) (Taverna et al. 2020, Nucl Acids Res48:W385-W394) with default parameters and TMM normalization. For each individual dataset, adifferential gene expression analysis between responsive and non-responsive tumors was performed including BRAF, NRAS and NF1 mutational status as a covariate. We then ranked genes by their log2 fold change and combined the resulting rank by calculating the median rank product to identify metabolic genes that were consistently associated with α-PD1 immunotherapy response. We filtered rank-based meta-analysis results for genes associated with arachidonic acid metabolism. The arachidonic acid metabolism associated ranked gene list was subsequently visualized using the R package ggplot2 (v3.1.1). MaMa / HPGDS / 822 7.27. Bioinformatics For the in-house Single cell RNA-seq (scRNA-seq) data from immune cells was acquired from the Pozniaket al. Study (Pozniak et al.2022, BioRxiv doi.org / 10.1101 / 2022.08.11.502598). Briefly the study includedtreatment naïve stage III / IV (AJCC 8thedition) melanoma patients receiving α-PD-1 based therapy (α-PD- 1 monotherapy (nivolumab): n=17; α-PD-1 and α-CTLA-4 combination therapy (ipilimumab + nivolumab): (n=6) SPECIAL trial; UZ / KU Leuven #S62275). Cutaneous, subcutaneous or lymph node metastases were biopsied before initiation of therapy (before treatment; BT). Subsequently, a second tumour biopsy wascollected right before the administration of the second ICB treatment cycle (early on-treatment; OT).Response of the patients to the treatment was stratified based on RECISTv1.1. Immune cells were identified based on unsupervised clustering and differentially expressed genes per cluster. The scRNA-seq data for the YUMM1.7 tumor model and melanoma patients were sourced from two GEOdatasets with the following accession numbers: GSE146613, GSE115978, and GSE120575. These datasetscontained a total of 4,665 cells from 6 mice and 4,861 cells from 31 patients, respectively. Furtherdownstream analysis was performed in R v.4.2.3 using the Seurat package (v4.3.0) (Stuart et al. 2019,Cell 177:1888-1902). Cells were filtered out if they had fewer than 200 or more than 6,000 detected genes or if mitochondrial transcripts constituted more than 10% of the reads. Similarly, genes were excluded if they were detected in fewer than three cells. These cells underwent scaling after normalization through a linear regression model that utilized the log-normalization method. Cells were clustered using the "FindNeighbors" function with 20 dimensions of reduction and the "FindClusters" function with default settings. Uniform Manifold Approximation and Projection (UMAP) was utilized for visualizing the clusters. Differential gene expression analysis between each cluster was performed using a Wilcoxon rank-sum test. In the murine scRNA-seq dataset, previously reported marker genes were used to annotate different macrophage subpopulations, including M1-like Macrophages (C1qa, Cd80, Cd86, Itgax, Tlr2, Fcgr1, Il1b) and M2-like Macrophages (C1qa, Mrc1, Sepp1, Ctsb, Retnla, Cd200r1). In the human scRNA-seq dataset, similar subpopulations were identified as M1-like Macrophages (C1QA, FCN1, CD80, CXCL9, CXCL10, SOCS3) and M2-like Macrophages (C1QA, SPP1, SEPP1, CD163, CD28, MSR1, SLC40A1). The R package ggplot2 v3.4.1 was used to check HPGDS expression in different clusters of cells.7.28 In vivo treatmentsFor the treatment with αPD1 (BioLegend, 114122, RRID: AB_2800578) mice were randomized when the average of the tumor volumes was 150 mm3and treated i.p. two times per week with 10 mg / kg αPD1 or control IgG from rat serum (Sigma-Aldrich, I4131, RRID: AB_1163627). For CD4 depletion, mice were treated three days before tumor injection (500 µg / mouse), then two times per week (250 µg / mouse) until the end of the experiment with αCD4 (BioXCell, BE0003-1, RRID: AB_1107636). The efficiency of MaMa / HPGDS / 822 CD4 depletion was assessed by FACS in the blood. For CD8 depletion, mice were treated i.p. with 5 mg / kg αCD8 (BioXcell, BE0117, RRID: AB_10950145) or control IgG from rat serum. Treatment with αCD8 was performed three days before tumor injection, then one time per week until the end of the experiment. The efficiency of CD8 depletion was assessed by FACS in the tumor. For the pharmacological inhibition of HPGDS, mice were treated by oral gavage with HQL-79 (Cayman Chemical Company, 10134, RRID:AB_3662692) (15 mg / kg BID), 1,8-naphthyridine 1y (in short, Cmpd1y) (GSK) (0.1 – 0.3 – 1 – 3 mg / kgBID), TAS-205 MedChemExpress, HY-109134A, RRID: AB_3662693) (30 mg / kg BID) or control vehicle (methylcellulose). For the engrafted melanoma mouse models, mice were randomized when the average tumor reached 100 mm3and treated two times per day with the indicated compound. For the genetically engineered mouse melanoma model, treatment with HQL-79 15 mg / kg BID, αPD1 10 mg / kg, the combination of both or with Vehicle and IgG started when the average tumor volume was 500 mm3). For the KPC model, 6 days after tumor injection, mice were treated intraperitoneally with 10 mg / kg αPD1, control IgG from rat serum. For the pharmacological inhibition of HPGDS, mice were treated for 9 days by oral gavage with HQL-7915 mg / kg BID or control vehicle (methylcellulose). 7.29 TAM-like macrophages To differentiate BMDMs towards TAM-like cells, 4x106BMDMs were seeded in 6-well plates in DMEM supplemented with 10% FBS, 1% P / S and 20% TCM for 12h at 37°C in a 5% CO2humidified atmosphere, as previously described. 7.30 HPGDS regulation in BMDMs BMDMs were isolated as described before. At day 6, were stimulated for 24h with 20 ng / ml IFN-γ and 100 ng / ml LPS, 10 ng / ml IL-4, 10 ng / ml IL-6 or 5 ng / ml IL-10. After 24hr, IL-4 polarized macrophages were treated for an additional 24hr with 20 ng / ml IFN-γ, 10 ng / ml TNFα, or 100 ng / ml LPS, alone or incombination. Unstimulated BMDMs were used as controls. Hpgds expression level was checked by qPCR.7.31 PGD2release by macrophages BMDMs were isolated as described before. At day 1x106macrophages were seeded in a 24-well plated and stimulated or not with for 24hr 10 ng / ml IL-4. IL-4 polarized macrophages were then treated for an additional 24hr 10 ng / ml TNFα. After that, medium was replaced with 200 µL of DMEM complete and conditioned for an additional 48hr. The day of the collection, secreted PGD2 was stabilized by adding Methoxime (MOX) and measured with Prostaglandin D2-MOX ELISA Kit (Cayman Chemical, 512011) in accordance with the manufacturer’s protocol. 7.32 HPGDS regulation in hMDMs hMDMs were obtained from healthy donor buffy coats and isolated with CD14-conjugated MicroBeads (Miltenyi Biotec) as described before. At day 6, hMDMs were stimulated for 24hr with 20 ng / ml IL-4 or 40 ng / ml IL-10. Unstimulated hMDMs were used as controls. After 24hr-stimulation, IL-4 polarized MaMa / HPGDS / 822macrophages were treated for an additional day with 10 ng / ml TNFα. HPGDS expression level waschecked by qPCR. 7.33 In vitro T cells with macrophages 24hr before starting the co-culture, IL-4 polarized or Ctrl macrophages were collected, seeded in 24-well plates, and incubated overnight at 37°C in a 5% CO2 humidified atmosphere. When indicated, macrophages were pre-treated for 24hr with 1µM of PGD2. To obtain T cell-conditioned media (T cell CM), 1 x 106activated CD4+T cells or CD8+T cells were cultured in a 6-well plate 24hr in T cell medium (RPMI supplemented with 10% FBS, 1% P / S, 1% MEM non-essential amino acids NEAA, 25 µmol / L β- mercaptoethanol, and 1 mmol / L sodium pyruvate). IL-4 polarized or Ctrl macrophages were thencultured with 250 µL T cell CM for 24hr at 37°C in a 5% CO2 humidified atmosphere. In the co-cultureexperiment, macrophages were co-cultured with activated CD4+T cell or CD8+T cells in a ratio 1:1 and incubated 24h at 37° C in a 5% CO2 humidified atmosphere. When indicated, 25 µg / ml αTNFα, 20 µg / ml αIFNy or Isotype Ctrl were added to the medium. Upon the indicated time of incubation, qPCR to assessHpgds expression in macrophages was performed.7.34 PGD2supplementation on CD8+T cells 1 x 106activated CD8+T cells were cultured in a 6-well plate 24hr in T cell medium before the addition of 1 mM of PGD2. Cells were then cultured for an additional 4hr in the presence or not of PGD2. Upon the indicated time of incubation, flow cytometry to assess cytokines production (i.e., GZMB, TNFα, IFNy), activation status (i.e., CD69) and PD1 expression was performed. 7.35 CD8+T cell proliferation Ovalbumin-specific OT-I CD8+T cells pre-activated with 1µg / ml of the OT-I TCR-binding ovalbumin peptide (IBA Lifesciences) cultured with 10 ng / ml IL-2 (Peprotech) were treated for 4hr with 1mM PGD2and then labeled with 5 µM CellTrace Violet (CTV, Invitrogen, C34571) for 15 min at 37ºC. OT-I expressing cells were then co-cultured with pre-seeded OVA-expressing YUMM 1.7 for 24hr in the presence of 1mM PGD2 at a ratio 2:1 (2 CD8+T cells:1 cancer cell). Cells were then stained with viability dye. Data were collected and analyzed with BD FACSDiva. 7.36 CD8+T cell cytotoxicity Ovalbumin-specific OT-I CD8+T cells pre-activated with 1µg / ml of the OT-I TCR-binding ovalbumin peptide (IBA Lifesciences) cultured with 10 ng / ml IL-2 (Peprotech) were treated for 4hr with 1mM PGD2and then labeled then co-cultured with pre-seeded OVA-expressing YUMM 1.7 in the presence of 1mM PGD2for 24hr at a ratio 2:1 (2 CD8+T cells:1 cancer cell). CD8+T cell cytotoxicity activity was determined with the Cytotoxicity Detection LDH Kit (Roche, 11644793001), according to the manufacturer’s instruction. MaMa / HPGDS / 822 7.37 CD8+T cell migration Migration of CD8+T cells was assessed by using a 5-μm-pore polycarbonate membrane (Transwell; Costar). When indicated CD8+T cells were pre-treated with 1 µM PGD2for 4hr. The bottom chambercontained T cell medium with or without 20ng / mL CXCL10 or 2x105 IL-4 polarized BMDMs Hpgds-WT orHpgds-KO pre-treated or not with 1 µM PGD2 for 24hr.12hr before starting the assay, CD8+T cells and macrophages were cultured in T cell medium (RPMI supplemented with 2% FBS, 1% P / S, 1% MEM non- essential amino acids NEAA, 25 µmol / L β-mercaptoethanol, and 1 mmol / L sodium pyruvate). Subsequently, 2x105CD8+T cells were seeded and incubated for 2hr. The migrated cells were collected and counted under the microscope. 7.38 Patient derived organotypic spheroid (PDOT) Human melanoma sample was received in cold RPMI complete (10% FBS, 1% P / S) on ice and minced in 13.5 mL RPMI supplemented with 10% FBS, 0.5% P / S, 1.1 mg / ml Collagenase I (Thermo Fisher Scientific), 2.3 mg / ml Dispase II (Gibco) and 2.2 µl DNase I (Quiagen) and digested for 20 minutes at 37°C. Digested tissue was centrifuged 5 minutes at 1500 rpm, resuspended in RPMI complete and filtered using first a 100-µm and then a 40-µm pore mesh strainer to generate S2 fraction (40-100 µm) spheroid fractions. This fraction was then centrifuged at 1500 rpm for 5 minutes at 4°C and resuspended in the collagen, containing 2.5 mg / ml type I rat tail collagen (Corning) buffered with PBS 10X with phenol red and adjusted the pH to 7.4 using 0.5M NaOH. The mixture containing the spheroid embedded in the collagen was then loaded into the 3D microfluidic culture devices. Spheroids were then incubated for 40 minutes at 37°C to let the collagen solidified and then hydrated with DMEM supplemented with 10% FBS and 10% P / S. After 24hr PDOTS were treated with 1µM HQL-79 or with vehicle by refreshing the inhibitior every day for an additional 96hr. After 96hr-treatment, PDOTS were then digested by using the digestion medium, incubated for 15 minutes at 37°C, centrifuged and stained to assess by flow cytometry TAM polarization (i.e., HLA-DR), CD8+T cell and TNFα-released by CD8+T cells. 7.39 RNA-seq on TAMs sorted from YUMM 1.7 Ctrl and HpgdsΔMømiceTotal RNA was isolated from in vivo sorted Hpgds KO and Ctrl TAMs (Vaibility-, CD45+, CD11b+, F4 / 80+)using the RNeasy Minikit (Qiagen) following the manufacturer's protocol and resuspended in RNase-free water. Frozen RNA samples were shipped to Novogene for the Plant and Animal Eukaryotic Strand Specific mRNA (WOBI) service and the resulting paired-end 150bp reads were sequenced on a NovaseqX Plus instrument. Next, reads were aligned to the mus musculus reference genome GRCm39 using STAR(v2.7.10b) with default parameters resulting in an average of 33.6 million uniquely mapped reads per sample. Aligned reads were quantified using featureCounts (v2.0.1) in R (v4.3.3) with options -t gene and -s 2. Subsequent analyses were performed with DESeq2 package (v1.42.0)(96). Gene Set Enrichment Analysis (GSEA) was conducted with clusterProfiler (v4.10.0) and org.Mm.eg.db (v3.18.0) and visualized MaMa / HPGDS / 822using DOSE (v3.28.1) and enrichplot (v1.22.0) (Wu et al. 2021, Innovation 2:100141; Yu et al. 2015,Bioinformatics 31:608-609). Marker genes of Mrc1-immunosuppressive macrophages were defined above. The “Angiogenesis related cytokines signature includes Fgf2, Pdgfc, Egf, Hgf, Pdgfa, Tgfa, Angpt2,Vegfc, Angpt1, Pdgfb, Vegfa, Vegfb, Igf1 and Pigf.7.40 Analysis of data from TCGA Gene expression and clinical data for TCGA SKCM were obtained from cBioPortal (https: / / www.cbioportal.org / datasets). The gene expression values were normalized to Transcripts Per Million (TPM) for subsequent analysis. The infiltration of 22 types of immune cells in each melanoma sample was determined using the CIBERSORT package (v0.1.0) in R software. Gene set permutations were set at 1000 repeats for each analysis. The R package ggpubr (v0.6.0) was employed to elucidate the differences between TME scores and HPGDS levels in these patients. To investigate the expression of HPGDS in human PDAC Normalized RNA-sequencing (RNA-seq) expression data from 181 PDAC tissue samples and 167 normal pancreatic samples were obtained from cBioPortal and the Genome–Tissue Expression (GTEx) project (https: / / www.genome.gov / Funded-Programs-Projects / Genotype-Tissue- Expression-Project), respectively. HPGDS expression levels were compared between tumor and adjacent normal / healthy tissues using both the TCGA and GTEx datasets. The Limma package was used to adjust batch effects between the two datasets. Gene expression distributions are presented as box plots, withstatistical significance calculated using the Wilcoxon test.

Claims

MaMa / HPGDS / 822 CLAIMS1. An inhibitor of hematopoietic prostaglandin D synthase (HPGDS) for use in treating a tumor orcancer, inhibiting a tumor or cancer, or inhibiting progression of a tumor or cancer.

2. The inhibitor of HPGDS for use according to claim 1, wherein the tumor or cancer is a primary tumoror cancer.

3. The inhibitor of HPGDS for use according to claim 1 or 2 in combination with immune checkpointinhibitor therapy, wherein the tumor or cancer is poorly responding or non-responsive to immune checkpoint inhibitor therapy.

4. The inhibitor of HPGDS for use in potentiating treatment with an immune checkpoint inhibitor of atumor or cancer that is poorly responding or non-responsive to immune checkpoint inhibitor therapy.

5. The inhibitor of HPGDS for use according to any one of claims 1 to 4, wherein the tumor or cancermicro-environment of the tumor or cancer is characterized in that the total amount of expression of HPGDS in the tumor micro-environment is predominantly contributed by tumor- or cancer-associated macrophages.

6. The inhibitor of HPGDS for use according to any one of claims 1 to 5 wherein the inhibitor of HPGDSis selectively inhibiting function or expression of HPGDS.

7. The inhibitor of HPGDS for use according to any one of claims 1 to 6 in combination with a furtheranti-tumor or anti-cancer agent, and / or in combination with surgery or radiation.

8. An isolated macrophage substantially lacking functional HPGDS, an isolated HPGDS knock-outmacrophage, or an isolated macrophage conditionally expressing an inhibitor of HPGDS.

9. The isolated macrophage according to claim 8 which is a CAR-macrophage or TCR-macrophage.

10. A combination of an immune checkpoint inhibitor and an inhibitor of HPGDS, an isolatedmacrophage substantially lacking functional HPGDS, an isolated HPGDS knock-out macrophage,and / or an isolated macrophage conditionally expressing an inhibitor of HPGDS.MaMa / HPGDS / 82211. The isolated macrophage according to claim 8 or 9 or the combination according to claim 10 for useas a medicament.

12. A method for selecting a subject having cancer for therapy including an inhibitor of HPGDS, anisolated macrophage substantially lacking functional HPGDS, an isolated HPGDS knock-out macrophage or an isolated macrophage conditionally expressing an inhibitor of HPGDS, comprising:assessing the expression of HPGDS in a tumor biopsy sample obtained from the subject, and selecting a subject having cancer for therapy including an inhibitor of HPGDS, an isolated macrophage substantially lacking functional HPGDS, an isolated HPGDS knock-out macrophage oran isolated macrophage conditionally expressing an inhibitor of HPGDS, when the total amount ofexpression of HPGDS in the tumor micro-environment of the tumor biopsy is predominantlycontributed by or occurring in tumor- or cancer-associated macrophages.

13. A method for determining response of subject having cancer to immune checkpoint inhibitortherapy or to therapy including an immune checkpoint inhibitor, comprising: assessing theexpression of HPGDS in an on-therapy tumor biopsy sample obtained from the subject, anddetermining the subject to respond to immune checkpoint inhibitor therapy or to therapy including an immune checkpoint inhibitor when the level of HPGDS expression in the on-therapy tumorbiopsy sample corresponds to reference on-therapy tumor biopsy sample HPGDS expression levelsthat are indicative of response of a subject having the cancer to the therapy including an ICI or to the therapy with an ICI.

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