IRF1 and infection: We also found that two avian (dOASL and oOASL) and two mammalian (hOASL-3D and mOasl2) enzymatic OASLs significantly increased the expression of RNase L and 10 (IRF1, IRF7, IFNα, IFNβ, IFNAR1, JAK1, STAT1, MX1, PKR, and TNFα) or six (IRF3, IFNα, IFNβ, IFIT1, IL8, and TNFα) genes related to IFN signaling in DF1OASL−/− cells or in A549 cells after infection with the H5N1 (CK/0513 or PR8) virus (Figures 3 and 4).