AGT and acute respiratory distress syndrome: The balance of the classical and alternative RAS has been studied in chronic heart (14, 15) and kidney (16) diseases, and the increased activation of the alternative RAS, together with a reduced Ang II/Ang I ratio, has been observed in mechanically ventilated patients with acute respiratory distress syndrome (ARDS) caused by various triggers (17, 18), including coronavirus disease 2019 (COVID-19) (19).