ACE2 and COVID-19: Earlier research has shown that the virus suppresses the ACE2 expression in SARS-CoV as well as MERS,60,61 and this has now been proved in SARS-CoV 2 also.62 ACE2 knockout mice were used in a previous study to reveal the involvement of ACE2 in acute respiratory distress syndrome (ARDS), a pulmonary complication of COVID-19.