The study has pointed out the key role of ACE2 in acute lung injury through a clinical report of COVID-19 patients, in which ACE, angiotensin II, and angiotensin II type 1a receptor (AT1a) promote the development of the disease and induce pulmonary edema causing impairment of lung function (Verdecchia et al., 2020). Here, ACE2 is linked to COVID-19.