The VEGF superfamily has six core members: VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, and PlGF. VEGF-A, to which VEGF 165 belongs, is the most widely studied, physiologically crucial, and considered VEGF in the narrow sense. VEGF is a potent growth and angiogenic cytokine. It stimulates proliferation and survival of endothelial cells, and promotes angiogenesis and vascular permeability. Expressed in vascularized tissues, VEGF plays a prominent role in normal and pathological angiogenesis. Substantial evidence implicates VEGF in the induction of tumor metastasis and intra-ocular neovascular syndromes. VEGF signals through the three receptors; fms-like tyrosine kinase (flt-1), KDR gene product (the murine homolog of KDR is the flk-1 gene product) and the flt4 gene product. VEGF 165 stands as the most prominent and biologically active protein isoform within the VEGF-A family.