IRF1 and infection: In addition, we observed significant up-regulation of many other genes related to IFN signaling pathways, such as IFIT1, IFIT2, IFIT3, IFIT5, RSAD2, OASL, GSP1, HERC5, IFI44, IFI44L, CD274, GBP2, GBP4, OAS2, DDX60, EIF2AK2, IRF1, BST2, and MNDA. All of these data clearly indicate that at the early stages of infection, influenza A H5N1 virus strongly activates a more prominent IFN signaling through RLRs, when compared with H1N1 virus infection.