CXCL12 and neoplasm: In OS intratumoral interleukin 6 (IL-6), interleukin 8 (IL-8), stromal derived factor 1 SDF-1 (known also as C–X–C motif chemokine 12—CXCL12), chemokines (C–C motif) ligand 5 (CCL5) and vascular endothelial growth factor (VEGF) promote OS cell growth and angiogenesis in the tumor, as well as metastatic spread [140,141].