ACE2 and COVID-19: It should be noted that type I IFNs can upregulate the gene expression and cellular levels at the receptor angiotensin-converting enzyme 2 (ACE2) of the cell invaded by SARS-CoV-2, and the increase of ACE2 receptor will lead to the aggravation of COVID-19 (Zamorano Cuervo and Grandvaux, 2020; Ziegler et al., 2020).