Recombinant Human VEGF Protein, Plant Vascular endothelial growth factor (VEGF), originally known as vascular permeability factor (VPF), is a signal protein produced by cells that stimulates the formation of blood vessels. It is a member of the PDGF family that is characterized by the presence of eight conserved cysteine residues and a cystine knot structure. It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate such as in hypoxic conditions.