VEGF was initially identified in conditioned medium from bovine pituitary follicular cells. VEGF-A belongs to the VEGF family, which has the following members: VEGF-A, VEGF-B, VEGF-C (VEGF-2), VEGF-D, and PlGF (placental growth factor). In addition, viral VEGF homologs (collectively called VEGF-E) and snake venom VEGFs such as T.f. (Trimeresurus flavoviridis) and svVEGF (called VEGF-F) have been described. VEGFA is alternatively spliced to generate variants with different number of amino acids such as VEGFA121, VEGFA145, VEGFA165, and VEGFA189. VEGFA121 is freely diffusible and does not bind to heparin sulphate, VEGFA165 and VEGFA189 bind to heparin sulphate, resulting in retention on the cell surface or in the extracellular matrix. VEGF-A is highly expressed in solid tumors generated in breast, lung, renal, colorectal and liver tissues. VEGF has strong vascular permeability activity and significantly contributes to the formation of ascites tumors. VEGF can act as a direct proinflammatory mediator during the pathogenesis of rheumatoid arthritis (RA) and protect rheumatoid synoviocytes from apoptosis, which contributes to synovial hyperplasia. VEGF is expressed in synovial macrophages and synovial fibroblasts in RA patients. Also, VEGF is associated with age-related macular degeneration (AMD). AMD is due to neovascularization that originates from endothelial cells in the choroid that grow into neurosensory retina as choroidal neovascularization (CNV).