CSF1 and neoplasm: The recruitment of macrophages to tumors is largely dependent upon soluble factors released into the circulation by the tumor, including CCL2, CCL5, VEGF, Endothelins, endothelial monocyte activating polypeptide (EMAP) II and colony stimulating factor 1 (CSF1), resulting in the mobilization of monocytes from the bone marrow (Murdoch et al., 2004; Franklin et al., 2014).