ANGPT1 and neoplasm: At the same time, a number of factors such as vascular endothelial growth factor (VEGF), hypoxia, fibroblast growth factors (FGF-1, FGF-2), platelet growth factor (PDGF), angiopoietin-1 (ang-1) and others, produced by the stroma, endothelium, tumor cells and blood, as well as the extracellular matrix, are able to stimulate tumor angiogenesis.