ICOS and COVID-19: ILC2s from COVID-19 patients showed upregulated expression of the genes IL4R (adj.p =8.3e-30) and ICOS (adj.p = 6.2e-05), which play important roles in ILC2 homeostasis and function, as well as expression of the transcription factor STAT3 (adj.p = 1.4e-03) (Figure 3B), RORA (adj.p = 0.001), important in development of ILC2 cells, and NAMPT (adj.p = 0.002) (Supplementary Data File 1).