Vascular endothelial growth factors (VEGF) are a subfamily of growth factors, specifically belonging to the platelet-derived growth factor (PDGF) family of cystine knot growth factors. They are important signaling proteins involved in angiogenesis (formation of the embryonic circulatory system from the ground up) and angiogenesis (formation of blood vessels from the growth of the pre-existing vascular system).VEGF stimulates both angiogenesis and angiogenesis. It can be involved in reverting the tissue oxygenation system when circulation is inadequate.The most important role of VEGF is angiogenesis. During embryogenesis, VEGF regulates the proliferation, migration, and survival of endothelial cells, which in turn regulates blood vessel density and size, but does not determine the type of blood vessel. In patients with bronchial asthma and diabetes, serum contains high concentrations of VEGF, which causes disease when overexpressed. Solid tumors are limited in size when the blood supply is inadequate; tumors that express VEGF grow and metastasize. overexpression of VEGF causes vascular disease in the retina of the eye and other parts of the body. Bevacizumab and ranibizumab inhibit VEGF and control or slow the disease process.