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. May play a role in increasing vascular permeability during lactation, when increased transport of molecules from the blood is required for efficient milk protein synthesis (By similarity). 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 (PubMed:26503042). Also binds the DEAR/FBXW7-AS1 receptor (PubMed:16293765). Homodimer; disulfide-linked (By similarity). Also found as heterodimer with PGF (By similarity). Interacts with NRP1 (PubMed:26503042). Interacts with isoform 2 of BSG (By similarity). Remains cell-surface associated unless released by heparin. In developing embryos, expressed mainly in the choroid plexus, paraventricular neuroepithelium, placenta and kidney glomeruli. Also found in bronchial epithelium, adrenal gland and in seminiferous tubules of testis. High expression of VEGF continues in kidney glomeruli and choroid plexus in adults. Levels increase during pregnancy (maximum 5.5-fold at 5 days) and a more marked increase occurs during lactation (maximal 9.7-fold at 7 days). Levels decrease progressively during the phase of involution. By IL-6 and FSH in vitro. Isoform VEGF-3 contains a basic insert which acts as a cell retention signal. Produced by alternative promoter usage and alternative initiation. Starts at an alternative upstream CUG codon. Belongs to the PDGF/VEGF growth factor family.