The expression of MDA5 and RIG1 was strongly induced by Sendai virus or poly(I:C), was maximal within 2 h of infection/transfection, was not observed in DEAF1−/− MEFs (Fig. 7, A and B, panels P5 and P6) and was prevented by Ruxolitinib and Tofacitinib (Fig. 7, C and D, panels P5 and P6 and supplemental Fig. S4). Here, IFIH1 is linked to infection.