Recent studies have evidenced the presence and activity of the renin–angiotensin system in T2D in various tissues, with observable changes in angiotensinogen, renin, ACE, aldosterone, angiotensin II, AT1R, AT2R, Ang 1-7 and Ang 1-9 in bones [22,25]. The gene discussed is REN; the disease is type 2 diabetes mellitus.