IFIT1 and infection: In accordance with the in vivo results, SARS-CoV-2-∆8 infection induced higher expression levels of IFN-β and pro-inflammatory cytokines than SARS-CoV-2-WT at 24 hpi and lower levels of IFN-β, IFN-λ, and IFIT1 at 72 hpi (Fig. 8).