CXCL12 and neoplasm: Different chemokines and growth factors, including colony-stimulating factor(CSF)-1, monocyte chemoattractant protein (MCP)-1/CCL-2, CCL-3, CCL-4, CCL-5, CCL-7, CCL-8, CXCL-12, interleukin (IL)-10, vascular endothelial growth factor (VEGF), and platelet derived growth factor (PDGF), secreted by tumor or stromal cells, recruit blood circulating monocytes which then differentiate into TAMs in the tumor site [6].