Also, IL-6, M-CSF, MCP-1 and stromal cell-derived factor-1 can be secreted by CAFs to promote macrophages infiltration and differentiation [148], while M2 could relatively secrete TGF-β to promote endothelial-to-mesenmal transition and increase reactivity of CAFs, thus enhancing invasiveness of cancer cells [149]. This evidence concerns the gene CCL2 and cancer.