When suffering from hypoxia and nutrient-deprived conditions, the tumor and surrounding stromal cells and endothelial cells begin to secrete pro-angiogenic factors, such as VEGF, angiopoietin, platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-β), fibroblast growth factor (FGF), and some growth factors promotes angiogenesis [271]. Here, TGFB1 is linked to neoplasm.