Vascular endothelial growth factor B (VEGFB) is a homodimeric, heparin-binding glycoprotein member of the VEGF family of growth factors. Compared to VEGFA, VEGFB’s main role is the maintenance of newly formed blood vessels and is involved in endothelial cell physiology. It is a ligand for vascular endothelial growth factor receptor 1 (VEGFR1) and neuropilin-1 (NRP1), while the binding of neuropilin-1 to VEGFB186 is proteolysis regulated.