ACE2 and infection: Consistently, we found using a previously published microarray dataset on mice lung upon SARS‐CoV infection (Gralinski et al., 2018; Totura et al., 2015), ACE2 mRNA is transiently upregulated at low SARS‐CoV titer but repressed at higher dosage or with time after infection, by day 4 even the lowest dosage tested suppressed ACE2 expression (Figure 3b).