PADI4 and COVID-19: We identified a comparably heightened expression of alarmin genes S100A8/9/12 toll-like receptors TLR4/8, together with markedly increased neutrophil activation-associated signatures PADI4, ELANE, OSM, and anti-apoptotic BCL2A1, PLAC8, and CLU in neutrophil subsets from both KD and severe COVID-19 patients (S1 cells in Figure 6).