Vascular endothelial growth factor (VEGF or VEGF-A), also known as vascular permeability factor (VPF), is a potent mediator of both angiogenesis and vasculogenesis in the fetus and adult . It is a member of the PDGF family that is characterized by a cystine knot structure formed by eight conserved cysteine residues . Alternately spliced isoforms of 121, 145, 165, 183, 189, and 206 amino acids (aa) have been identified in humans, with 120, 164 and 188 aa isoforms found in mouse . VEGF binds the type I transmembrane receptor tyrosine kinases VEGF R1 (also called Flt-1) and VEGF R2 (Flk-/KDR) on endothelial cells .Although affinity is highest for binding to VEGF R1, VEGF R2 appears to be the primary mediator of VEGF angiogenic activity . Human VEGF165 binds the semaphorin receptor, Neuropilin-1 and promotes complex formation with VEGF R2 . VEGF is required during embryogenesis to regulate the proliferation, migration, and survival of endothelial cells . In adults, VEGF functions mainly in wound healing and the female reproductive cycle . Pathologically, it is involved in tumor angiogenesis and vascular leakage . Circulating VEGF levels correlate with disease activity in autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. VEGF is induced by hypoxia and cytokines such as IL-1, IL-6, IL-8, oncostatin M and TNF-α . Synonyms: Vascular endothelial growth factor A, VEGF-A, Vascular permeability factor, VPF, VEGFA, VEGFA164, VEGF164