Mammalian members of the VEGF family include VEGF (VEGF-A), -B, -C, -D, and the closely related PlGF (placenta growth factor). They are disulfide-linked dimeric proteins that are best known as regulators of physiological and pathological vasculogenesis, angiogenesis, and lymphangiogenesis. Receptors for VEGF family ligands include the tyrosine kinases VEGF R1 (Flt-1), VEGF R2 (KDR or Flk-1), VEGF R3 (Flt-4), and the Neuropilins. Family members exhibit preference for specific receptors. For instance, VEGF R1 and VEGF R2 are receptors for VEGF, while VEGF R2 and R3 act as the receptors for VEGF-C and -D. VEGF R2 appears to be the primary mediator of VEGF angiogenic activity. Other diverse functions for the VEGF family include mediating neurotrophic activity and regulating hematopoietic development.