CXCL8 and neoplasm: Many angiogenic factors, including VEGF, bFGF, TGF-α, TGF-β, TNF-α, platelet-derived endothelial growth factor (PDEGF), granulocyte colony-stimulating factor (GM-SF), placental growth factor, IL-8, and epidermal growth factor, promote the process of angiogenesis [33], and these angiogenic activators play important roles in the growth and spread of tumor cells [34].