TNF and neoplasm: Growth factors of tumor angiogenesis can either involve specific vascular endothelium factors (i.e., vascular endothelial growth factor (VEGF), angiopoietin and ephrin family members), or non-specific factors (i.e., platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), fibroblast growth factor (FGF) or tumor necrosis factor-α (TNF-α)) [8].