IFNB1 and infection: We performed IFN-β promoter-driven luciferase assay in 293T cells (Figure 1D), and quantitative PCR (Figure 1E,G) and ELISA assays (Figure 1F) in BMDMs in response to transfected Poly (I:C) or infection of SeV, VSV or IAV with the NS1R38A/K41A mutant (IAV-mut, which induces high levels of IFN-β, [Donelan et al., 2003]), respectively.