ACE2 and acute respiratory distress syndrome: Interestingly, a recombinant human soluble ACE2 (rhsACE2), corresponding to the extracellular domain of ACE2, was developed several years ago and found to be safe in healthy volunteers and in a small cohort of patients with acute respiratory distress syndrome (ARDS) in completed Phase I and Phase II clinical trials (ClinicalTrials.gov identifier: NCT00886353) (Haschke et al., 2013; Khan et al., 2017).