By analyzing human, non-human primate, and mouse single-cell RNA-sequencing (scRNA-seq) datasets and identifying ACE2 and TMPRSS2 co-expressing cells in lung type II pneumocytes, ileal absorptive enterocytes, and nasal goblet secretory cells, Ziegler et al. [82] showed that ACE2 is enhanced in human nasal epithelia and lung tissue by interferon and influenza but not upregulated in mice. Here, ACE2 is linked to influenza.