ACE2 and COVID-19: Interferons (IFNs) and ISGs are normally expressed in host cells as an antiviral and tissue-protective mechanism (Acharya et al. 2020; Ziegler et al. 2020), and it is hypothesized that upregulation of ACE2 by these responses could favor further SARS-CoV-2 infection in severe COVID-19 cases.