Tissue distribution of ACE2 in humans has been highly correlated with clinical manifestations of COVID-19 (Cao et al., 2020; Li et al., 2020a; Xu et al., 2020), including a possible explanation for atypical clinical manifestations of COVID-19 and different excretion ways (Li et al., 2005, 2020a). The gene discussed is ACE2; the disease is COVID-19.