ACE2 and acute respiratory distress syndrome: It is worth noting that intraperitoneal injections of recombinant human ACE2 protein at a dose of 0.1 mg kg−1 into mice has conferred protection against severe ALI, as measured by percentage change in lung elastance induced by acid aspiration (which mimics human ALI/ARDS, frequently caused by aspiration of gastric contents) (Imai et al. 2005).