Recombinant human vascular endothelial growth factor (VEGF)165 expressed in E. coli cells. Human VEGF exists in multiple molecular variants and are named based on the number of amino acids they contain. VEGF165 is the most common form of VEGF. It is a 38.2 kDa disulfide-linked homodimeric protein consisting of two 165 amino acid polypeptides.