CXCL12 and neoplasm: M2-like TAMs promote tumor angiogenesis by producing pro-angiogenic growth factors (VEGF, EGF, FGF family, and PDGF-b), angiogenic CXC chemokines (CXCL8/IL-8 and CXCL12, also known as SDF-1), and angiogenesis-associated factors (TGF-b, TNF-α, and thymidine phosphorylase)51,52.