We found some upregulated DEGs after Omicron breakthrough infection, including lymphocyte antigen 6E(LY6E) involved in T-cell development, S100A9 regulation of inflammatory processes and immune response, tumor necrosis factor ligand superfamily member 10(TNFSF10), XIAP-associated factor 1(XAF1) induced apoptosis and multiple interferon stimulated genes (including IFI6, IFI27, IFI44L, IFIT3, IRF7, ISG15, and IFITM1/2/3) (Figure 2A). The gene discussed is S100A9; the disease is infection.