IRF7 and infection: On 2 dpi, corresponding to the peak of infection, expression of ISGs, RLRs, STAT1, IRF7, IL8, CCL2, CCL3 and CASP1 were moderate to highly induced in MNNE areas from animals infected by both strains while most of the remaining genes were unaltered or slightly down-regulated upon infection (Figure 4(b), Supplementary Figure 3(a, c) and Supplementary Data S1).