Macrophages are initially recruited to the tumor sites through macrophage colony-stimulating factor 1 (CSF-1) signaling [38], and amplified through a variety of cytokines including C–C motif chemokine ligand 2 (CCL2), TNFα, vascular endothelial growth factor (VEGF), C-X-C motif chemokine ligand 12 (CXCL12), and TGFβ [26, 39–42]. The gene discussed is CCL2; the disease is neoplasm.