DPP4 and diabetes mellitus: Figure 2 schematically represents the cytoprotective effects of DPP-4 inhibitors on extrapancreatic organs/tissues targeted by diabetes, including the heart, vessels, kidney, and retina, which could be important to control the severe micro- and macrovascular complications found in diabetic patients, including cardiovascular events, end-stage renal disease (ESRD), and blindness.