Complications account for disabilities and high mortality rates in diabetes.[3] Aerobic cells are endowed with extensive antioxidant defense mechanisms including both low molecular weight scavengers such as reduced glutathione (GSH), ascorbic acid (vitamin C), Vitamin E and enzyme system such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px).[2] A non-enzymatic endogenous antioxidant GSH (reduced form) plays an important role against oxidative stress in diabetes. The gene discussed is CAT; the disease is diabetes mellitus.