miR200c, a negative regulator of ACE2 expression (Figure 6), is significantly enriched (Gupta et al., 2019) and induced by oxidative stress (Wu et al., 2017) and highly elevated in pneumonia and chronic obstructive pulmonary disease patients (Liu et al., 2017) and positively correlated with disease severity in interstitial lung disease (Jiang et al., 2017). Here, ACE2 is linked to chronic obstructive pulmonary disease.