Consistent with the PCA results, while COVID-19 and non-COVID-19 sepsis patients differed greatly by gene expression at D1 (1,215 DE genes), they became remarkably similar by D7 in the ICU, decreasing to only nine DE genes: HES4, KLHDC7B, KLHDC7B-DT, OTOF, OR2B6, IFI27, SIGLEC1 (upregulated), FAM83A, and CNR1 (downregulated) (Figure 3A). Here, HES4 is linked to COVID-19.