While during the early stage of reinfection, the most significant enriched GO terms of 31 upregulated DEGs in CD8+ Trm cells were related to the response to the virus, type I interferon signaling pathway, and interferon-beta (Figure 3C), which suggests that CD8+ Trm cells play a critical role in fighting against influenza reinfection. This evidence concerns the gene IFNB1 and influenza.