Tumor-associated macrophages (TAMs). Tumor cells recruit circulating monocytes from the peripheral blood into tumors mainly through the secretion of colony-stimulating factor-1 (CSF-1) and monocyte chemoattractant protein-1 (MCP1; also known as C-C motif chemokine ligand 2 (CCL2)) [59]. The gene discussed is CSF1; the disease is neoplasm.