IRF3 and viral infectious disease: Multiple pattern recognition receptors (PRRs), including Toll-like receptors (TLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), and cyclic GMP-AMP synthase (cGAS), detect viral infection, trigger the activation of interferon regulatory factor 3 (IRF3), and subsequently initiate the type I IFN expression2.