ACE2 and severe acute respiratory syndrome: The role of the renin-angiotensin-aldosterone system (RAS), particularly the role of ACE2 (angiotensin-converting enzyme 2) receptors, has been studied in SARS-CoV infections and appears to be associated with the progression of COVID-19 (McMillan and Uhal 2020[73]; Ni et al., 2020[85]).