ACE2 and acute respiratory distress syndrome: ACE2 is also the viral receptor for SARS-CoV-1.9 The cellular distribution of ACE2, on the vascular endothelium, kidney, heart, and lungs, may explain, in part, the frequent occurrence of acute kidney injury (AKI), acute cardiac injury (ACI), and acute respiratory distress syndrome (ARDS) in COVID-19 patients.10, , -13 SARS-CoV-2 binding to ACE2 leads to SARS-CoV-2 entry and downregulation of ACE2 at the cell membrane, similar to SARS-CoV-1.14 Other respiratory viruses also downregulate ACE2 expression (eg, influenza H1N1, H5N1, H7N9).15, -17