Animal-free Recombinant Human VEGF 165is expressed in human 293 cells as a homodimeric glycoprotein with an apparent molecular mass of 45 kDa. The E. coli expressed protein is a monomer-dimer mixture with a molecular mass 18 to 34 kDa. The cytokine is produced in a human cell expression system with serum free, chemically defined media. VEGF, also known as vascular permeability factor (VPF) or vasculotropin, is a homodimeric 34-45 kDa, heparin-binding glycoprotein with potent angiogenic, mitogenic, and vascular permeability enhancing activities specific for endothelial cells.