We generated tumor-educated macrophages (TEMs) by culturing Phgdhfl/fl and PHGDH-deficient BMDMs in tumor-conditioned media (TCM) derived from cancer cell lines with high PHGDH amplification; these cells included murine AE17 mesothelioma, human A549 lung cancer, human HCT116 colon cancer, and human MDA-MB-231 breast cancer cells without significant PHGDH amplification (Supplementary Fig. S2A). The gene discussed is PHGDH; the disease is breast cancer.