Since alteration of cytokine signaling did not affect the levels of PRRs and viral RNA and given that IRF3 is a known regulator of IFN expression at the early stage of infection, we determined whether there was a functional link between IFN-λ signaling and activation of nuclear factor of κB (NF-κB), a key transcriptional factor downstream of RIG-I pathway [31]. This evidence concerns the gene RIGI and infection.