Given the well-known detrimental effects of the classical ACE/Ang II/AT1R axis on the kidney and the emerging reno-protective effects of the alternative ACE2/Ang(1–7)/Mas axis, the present study was designed to investigate whether renal ACE deficiency may convey a protective effect against experimentally induced renal insufficiency. The gene discussed is ACE2; the disease is hyperinsulinemic hypoglycemia, familial, 4.