They are generally classified into two extreme phenotypes: M1 macrophages produce considerable pro-inflammatory cytokines, whereas M2 macrophages secrete several growth factors that activate the process of tissue repair and suppress adaptive immune responses.75 Macrophages accumulated in cancer are termed tumor-associated macrophages (TAMs).75 Tumor-derived signals such as M-CSF, CCL2, VEGF and angiopoietin-2 recruit blood monocytes through the tumor vessels and promote the polarization of macrophages in cancer sites.76, 77 TAMs exhibit an M2-like phenotype and possess pro-tumor immunity. Here, CSF1 is linked to cancer.