Extended Data Fig. 2: Markers used to identify and stratify the different cells of the upper respiratory tract.

a, Dot plot depicting the markers of the epithelial cell types. b, Dot plot depicting the markers used to identify the different immune cell types. Expression levels are color coded, the percentage of cells expressing the respective gene is size coded. For details on cell types and markers refer to Methods. Nasopharyngeal swab samples were used in this analysis: n = 5 control samples, n = 14 moderate COVID-19 samples, and n = 13 critical COVID-19 samples. Rel. Exp. = relative gene expression, Pct. Exp. = percentage of cells expressing the gene.