Growth factor active in angiogenesis, vasculogenesis and endothelial cell growth. Induces endothelial cell proliferation, promotes cell migration, inhibits apoptosis and induces permeabilization of blood vessels. Homodimer; disulfide-linked. Also found as heterodimer with PGF Interacts with FLT1/VEGFR1 and KDR/VEGFR2 receptors, heparan sulfate and heparin. Expressed by the venom gland. Belongs to the PDGF/VEGF growth factor family.