a, Expression of ACE2 (an entry receptor for SARS-CoV and SARS-CoV-2), ANPEP (an entry receptor for HCoV-229E), ST6GAL1/ST3GAL4 (enzymes important for synthesis of influenza entry receptors), and DPP4 (an entry receptor for MERS-CoV) from the airway epithelial datasets: Vieira Braga, Kar et al. 2019 (left panel) and Deprez et al. 2019 (right panel). The basic reproductive number (R0) for respective viruses, if available, are shown. b, Respiratory epithelial expression of the top 50 genes correlated with ACE2 expression based on Spearman’s correlation analysis (with Benjamini-Hochberg-adjusted p-values) performed on all cells within the Vieira Braga, Kar et al. airway epithelial dataset. The colored gene names represent genes that are immune-associated (GO:0002376: immune system process or GO:0002526: acute inflammatory response). For gene expression results in the dot plots: the dot size represents the proportion of cells within the respective cell type expressing the gene and the color represents the average gene expression level within the particular cell type.