Hyperglycemia activates two independently acting pathways: Activation of PKC-δ and P38α MAPK-mediated src homology-2 domain–containing phosphatase-1(SHP-1) overexpression to inactivate platelet-derived growth factor receptor-β(PDGFR-β) and activate the NF-κB cascade to induce apoptosis of retinal pericytes and endothelial cells. The gene discussed is PDGFRB; the disease is Hyperglycemia.