ACE2 and COVID-19: In addition to being a major receptor for SARS-CoV-2, ACE2 was originally discovered to be a negative regulator of the renin–angiotensin system (RAS) that functions by catalyzing the degradation of angiotensin II (Ang II) to Ang 1–7; which has also been recently reported to be associated with COVID-19 ([3, 4]).