AT-II cells abundantly express ACE2, which binds to the SARS-CoV-2 virus; after infection, AT-II cells trigger the inflammatory response, and autopsy studies of COVID-19 patients demonstrated the appearance of necrosis and cell hyperplasia of AT-II cells (Ackermann et al., 2020; Satarker et al., 2021). Here, ACE2 is linked to COVID-19.