Consistent with our findings of GRNs from existing scRNA-seq PBMCs (Figure 2; Supplementary Figures 4, 6), we discovered that the associated TFs were also expressed in the corresponding cell types and upregulated their target genes such as S100A8/A9 in severe COVID-19 (Supplementary Figures 10B, C). Here, IGKV1D-22 is linked to COVID-19.