RIGI and viral infectious disease: RT-qPCR analysis showed no significant differences between rPICV-infected WT and SKO and DKO mice in ISG responses (Figures 3B, D), indicating that these two KO mouse lines were somehow able to express these particular ISGs by day 3 post viral infection despite the lack of early IFN-I signaling mediated by the RIG-I and MDA5 pathway.