ACE2 and COVID-19: SARS-CoV-1 and SARS-CoV-2, which have been responsible for the SARS epidemic and for the COVID-19 pandemic, respectively, interface with the renin-angiotensin-aldosterone system (RAAS) through ACE2, an enzyme that modulates the effects of the RAAS but is also the primary receptor for both SARS viruses.