Although low concentration of VEGF is part of a pro-survival signaling in the hypoxic tissue with actions that include vasodilatation, endothelial cell survival, neuroprotection, neurogenesis [37], high concentration VEGF contributes retinal neovascularization and vascular leakage, which causes macular edema and proliferative diabetic retinopathy, respectively. The gene discussed is VEGFA; the disease is macular retinal edema.