MUC1, MUC2, MUC4, MUC16, and MUC20 mRNA expression strongly correlated with COVID-19 severity, of which MUC1 and MUC20 mRNA expression also associated significantly with age (Figure 6, A–C) and MUC16 and MUC20 mRNA expression with sex (Figure 6A). This evidence concerns the gene MUC20 and COVID-19.