When the balance between pro- and anti-angiogenic agents shifts towards pro-angiogenic agents including VEGF, as a fundamental player, and other factors such as b-FGF, epidermal growth factor (EGF), transforming growth factor β (TGF-β), tumor necrosis factor-alpha (TNF-α), angiogenin, angiopoietin, and interleukin 8 (IL-8) [37], several intracellular pathways are triggered leading to activation of endothelial cell proliferation and migration towards the tumor. This evidence concerns the gene CXCL8 and neoplasm.