ACE2 and respiratory failure: By analyzing these facts only, two contradictory conclusions can be drawn: ACE2 expression may be disadvantageous as it increases the possibility of virus entry into cells (the role of ACE2 as a receptor for SARS-CoV2) and b) an increase in ACE2 expression may be beneficial as it prevents acute respiratory failure by lowering angiotensin 2 and increasing angiotensin (1-7) levels.