For example, in the transgenic Ren2 rat preclinical model of hypertension, tissue RAS overexpression with increased renin and Ang II (10 weeks of age) demonstrated that only the islets were stained excessively with 3-nitrotyrosine as compared to the Sprague–Dawley control age-matched controls (Figure 6) [18,19]. Here, REN is linked to hypertensive disorder.