Interestingly, even if type I-diabetes subregulates the endothelial expression of Mas receptors in rat carotid, the activation of this residual population of receptors during the chronic treatment with Mas agonists can trigger antioxidant effects that are enough to overcome the impairment of the local ACE2-angiotensin-(1–7)-Mas axis functionality. The gene discussed is ACE2; the disease is type 1 diabetes mellitus.