Activation of the transcription factors IRF3 and NF-κB in response to infection with a single-stranded RNA virus. On viral infection, RIG-I activated by viral RNA interacts with the adaptor protein MAVS, which represents a bifurcation point for the activation of IRF3 and NF-κB via activation of distinct IKK family members. Activation of NF-κB involves phosphorylation of its cytoplasmic inhibitor IκBκ, which tags that protein for destruction with the consequent release of NF-κB. IRF3 and NF-κB in turn activate a number of genes important in the antiviral response, including that for IFNβ. NLRX1 has been recently shown to inhibit this pathway, possibly by blocking the interaction of RIG-I with MAVS.