Supplementary Figure 7A verifies that IRF1 expression is abolished constitutively or upon IFNβ treatment in the KO cell lines. Similar to the BEAS-2B cells, A549 cells also showed reduced level of STAT-1 phosphorylation in response to poly I:C stimulation (Supplementary Figure 7B), reduced level of constitutive MX1 expression and increased susceptibility to Influenza infection compared to the parent A549 cells (Supplementary Figures 7C–E). Here, MX1 is linked to influenza.