VEGF induces proliferation and migration of vascular endothelial cells, and is essential for both physiological and pathological angiogenesis. Although expressed at high levels in certain tumor-derived cells, it is produced by a wide variety of cell types. VEGF has several alternatively spliced isoforms, with VEGF-165 being the most abundant. rHu Vascular Endothelial Growth Factor expressed in E. coli is a non-glycosylated dimer, where each monomer is made up of 166 amino acids with a molecular mass of 19.3 kDa.