ACE2 and infectious disease: COVID-19 is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has rapidly evolved into a global pandemic.407 SARS-CoV-2 belongs to the coronavirus genus and is an enveloped, single-stranded ribonucleic acid (RNA) virus.408,409 The virus gains entry into the host cell by binding its spike protein (S protein) to the angiotensin-converting enzyme 2 (ACE2) receptor on the surface of host cells.