Although activation of NFκB- and/or AP-1 (c-JUN/ATF2)-mediated pathways could contribute to IFN-β gene induction [58], studies with targeted gene knockout (KO) mice have clearly indicated that IRF-3 and/or IRF-7 molecules play an indispensible, but distinctive, role in the induction of IFN-α/β responses against viral infection [59]. This evidence concerns the gene IFNA2 and viral infectious disease.