Individuals with diabetes can lead quite normal lives when their blood sugar is controlled by insulin injections. But these injections cannot maintain blood glucose at concentrations as low and stable as they are in normal individuals. The resulting highe r glucose concentrations eventually lead to the complications of diabetes—damage to blood vessels, heart disease, blindness, stroke, and kidney failure. In a report in this week's issue (Ishii et al., p. 728), a new inhibitor of protein kinase C is shown to inhibit some indices of glucose toxicity in an animal model of diabetes. In their Perspective, Porte and Schwartz discuss how close we are to being able to treat these complication s in patients.