RIGI and infection: However, we showed previously that MDA5 expression is not significantly induced during infection by EMCV, which is particularly effective at suppressing the IFN response,54,55 and that stimulation with poly(I:C) dsRNA did not induce IFNB1 expression in A549 RIG-I KO cells.59 Furthermore, western blot data showed that levels of endogenous MDA5 remained low compared to the overexpressed variants, following poly(I:C) stimulation (Figures 1B and 1C).