PLAU and PLAUR expression was also observed in a fraction of cells from a pro-fibrogenic KRT17+ KRT5- population in COVID-19 and PF patients (Figure 1B,C), though the overall number of PLAU+ and PLAUR+ cells in this population was still low (median normalized expression 0) (Figure 1B,C). This evidence concerns the gene KRT17 and pemphigus foliaceus.