CSF1R and cancer: In cancer, CSF-1R signaling facilitates the recruitment and survival of tumor associated macrophages (TAMs) in the tumor microenvironment, resulting in suppression of host anti-tumor immunity [3] The interaction between macrophages and tumor immunity is complex, with both pro- and anti-tumor subsets comprising the tumor infiltrate; macrophages promote tumorigenesis and metastases by numerous mechanisms, including secreting cytokines that enhance tumor proliferation and angiogenesis [4].