After being stimulated by hypoxia-inducible factor (HIF-1α), TAMs release a set of angiogenic cytokines, such as vascular endothelial growth factors (VEGF)-A (40), TGF-β, CXCL12, PDGF, and MMPs (7), which in turn promote tumor angiogenesis (40). This evidence concerns the gene CXCL12 and neoplasm.