IRF3 and infection: In cells co-transfected with both siTLR3 and siRIG-I, the mean IRF3 and IFN-β mRNA levels in H3N2 CIV-infected cells were 2.7- and 2.6-fold higher, respectively, than those in mock-infected cells at 18 h post-infection (Figs. 4A and 4B).