IFNA1 and COVID-19: When we directly compared mild or moderate to severe COVID-19, we found that multiple cell types show robust transcriptional changes, most drastically among ciliated cell subtypes (IFN-responsive ciliated cells, FOXJ1high ciliated cells, early-response FOXJ1high ciliated cells, developing ciliated cells), ionocytes, SERPINB11high secretory cells, early-response secretory cells, and AZGP1high goblet cells.