Growth factor active in angiogenesis, and endothelial cell growth, stimulating their proliferation and migration and also has effects on the permeability of blood vessels. May function in angiogenesis of the venous and lymphatic vascular systems during embryogenesis, and also in the maintenance of differentiated lymphatic endothelium in adults. Binds and activates KDR/VEGFR2 and FLT4/VEGFR3 receptors. Homodimer; non-covalent and antiparallel (PubMed:9247316). Interacts with FLT4/VEGFR3; the interaction is required for FLT4/VEGFR3 homodimarization and activation (By similarity). Expressed in adult heart, brain, spleen, lung, liver, skeletal muscle, kidney, testis and intestine with higher levels in heart, brain and kidney. Isoform 4 levels are very low. Isoform 3 is mostly expressed in liver and has reduced expression level in other tissues. Isoform 2 is mostly expressed in brain and kidney, although a lower level expression in other tissues is also detectable. Expression detected in mesenchymal cells of postimplantation embryos, particularly in the regions where the lymphatic vessels undergo sprouting from embryonic veins, such as the perimetanephric, axillary and jugular regions, and in the developing mesenterium. Also detected between vertebral corpuscles, in lung mesenchyme, in neck region and in developing forehead. Not detected in the blood islands of the yolk sac. Undergoes a complex proteolytic maturation which generates a variety of processed secreted forms with increased activity toward VEGFR-3, but only the fully processed form could activate VEGFR-2. VEGF-C first form an antiparallel homodimer linked by disulfide bonds. Before secretion, a cleavage occurs between Arg-223 and Ser-224 producing a heterotetramer. The next extracellular step of the processing removes the N-terminal propeptide. Finally the mature VEGF-C is composed mostly of two VEGF homology domains (VHDs) bound by non-covalent interactions (By similarity). Belongs to the PDGF/VEGF growth factor family.