IRF3 and viral infectious disease: IRF3 and IRF7 are the main regulators of type I IFN expression, when cells are stimulated with virus infection, IRF3 are phosphorylated by the serine/threonine kinases, TBK1 and IKKɛ, and then homodimerized IRF3 translocates from the cytosol into the nucleus and binds to responsive elements for IFN-β gene transcription [43].