Treatment with IFN-γ, which induces a pro-inflammatory type 1 (M1) phenotype in macrophages, also induced expression of PROS1 in 6 of 8 murine melanoma, lung cancer, breast cancer, and pancreatic cell lines tested and treatment with PROS1 or co-culture with wild-type B16.F10 melanoma cells, but not B16.F10 cells with CRISPR-mediated PROS1 knock-down, decreased M1 cytokine expression in M1-polarized macrophages [125]. Here, PROS1 is linked to breast cancer.