CCL2 and neoplasm: Chemokines such as CCL-2 (C-C motif chemokine ligand-2, also known as monocyte chemoattractant protein-1, or MCP-1), CCL-5, CXCL-12 (C-X-C motif chemokine ligand-12), the growth and differentiation factor M-CSF (macrophage colony-stimulating factor or colony-stimulating factor 1, CSF-1), cytokines and the vascular endothelial growth factors (VEGFs), are all examples of signaling molecules produced by tumor cells that act as recruiting and differentiating factors for M2-TAMs [11,12,13].