ACE2 and COVID-19: In contrast, increased activity of the non-classical RAAS pathway, reflected by high circulating levels of equilibrium Ang-1–7 and soluble ACE2 as well as an increased Ang-1–7/Ang-II ratio, appears to be a finding unique to critically ill COVID-19 patients, reproduced in both studies that implemented an LC-MS equilibrium approach (6, 7).