Specifically, several pathways including vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, platelet-derived growth factor (PDGF)B, the kallikrein-kinin system, advanced glycation end products, and the polyol pathway were shown to be involved in the pathophysiology of diabetic retinopathy (DR)13. The gene discussed is TNF; the disease is diabetic retinopathy.