Growth factor active in angiogenesis, vasculogenesis and endothelial cell growth. Induces endothelial cell proliferation, promotes cell migration, inhibits apoptosis and induces permeabilization of blood vessels. Binds to the FLT1/VEGFR1 and KDR/VEGFR2 receptors, heparan sulfate and heparin. NRP1/Neuropilin-1 binds isoforms VEGF-165 and VEGF-145. Isoform VEGF165B binds to KDR but does not activate downstream signaling pathways, does not activate angiogenesis and inhibits tumor growth. Binding to NRP1 receptor initiates a signaling pathway needed for motor neuron axon guidance and cell body migration, including for the caudal migration of facial motor neurons from rhombomere 4 to rhombomere 6 during embryonic development (By similarity). {ECO:0000250|UniProtKB:Q00731, ECO:0000269|PubMed:11427521, ECO:0000269|PubMed:16489009}.,Alternative sequence (12); Beta strand (9); Chain (1); Disulfide bond (5); Erroneous initiation (1); Glycosylation (1); Helix (4); Sequence caution (1); Sequence conflict (2); Signal peptide (1); Turn (4),By hypoxia. Regulated by growth factors, cytokines, gonadotropins, nitric oxide, hypoglycemia and oncogenic mutations. {ECO:0000269|PubMed:22009797}.,Isoform VEGF189, isoform VEGF165 and isoform VEGF121 are widely expressed. Isoform VEGF206 and isoform VEGF145 are not widely expressed. A higher level expression seen in pituitary tumors as compared to the pituitary gland. {ECO:0000269|PubMed:22009797}.,Microvascular complications of diabetes 1 (MVCD1) [MIM:603933]: Pathological conditions that develop in numerous tissues and organs as a consequence of diabetes mellitus. They include diabetic retinopathy, diabetic nephropathy leading to end-stage renal disease, and diabetic neuropathy. Diabetic retinopathy remains the major cause of new-onset blindness among diabetic adults. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. {ECO:0000269|PubMed:11978667}. Note=Disease susceptibility is associated with variations affecting the gene represented in this entry.