TMPRSS2 and infection: Using immunohistochemical analysis (Bertram et al., 2012) and, very recently, using single nuclei and single‐cell RNA sequencing (Lukassen et al., 2020), of lung samples from otherwise healthy subjects, ACE2 and TMPRSS2 were shown to be co‐expressed in human bronchial epithelial cells, which could be a nexus for primary infection.