Collectively, we propose the following potential roles of rACE2 in the treatment of SARS-CoV-2-induced ALI: 1) rACE2 directly binds SARS-CoV-2 spike RBD protein, thereby reducing the binding of SARS-CoV-2 spike RBD protein at endogenous ACE2; 2) rACE2 cleaves AngI to generate Ang1-9, thereby suppressing the conversion of AngI to AngII; and 3) rACE2 cleaves AngII to generate Ang1-7, thereby directly decreasing the levels of AngII (Fig. 10F). Here, ACE2 is linked to acute respiratory distress syndrome.