CXCL8 and neoplasm: Several growth factors, including VEGF, hepatocyte growth factor, angiopoietin-2, transforming growth factor (TGF)-α, stem cell factor, erythropoietin, colony-stimulating factor, fibroblast growth factor, and PDGF-BB, and pro-inflammatory cytokines, TNF-α and IL-8, may play a dominant role in promoting the proliferation of tumor cells.