Prof.Ryoichi Takayanagi et al. are studying about mechanisms of production of oxidative stress in diabetes. They found that the tissue renin-angiotensin system and protein kinase C are activated in hyperglycemia, and stimulate the NDA(P)H oxidase activity resulting in injury of both vessels in all organs and beta-cells in pancreas. They are challenging to make a new drug to suppress the oxdative stress in diabetes mellitus.