The angiotensin converting enzyme-1–angiotensin II–angiotensin AT1 receptor pathway contributes to the pathophysiology of ARDS, whereas activation of the ACE-2–angiotensin(1-7)-angiotensin AT2 receptor and the ACE-2–angiotensin(1-7)–Mas receptor pathways have been shown to be protective. This evidence concerns the gene AGT and acute respiratory distress syndrome.