IFNA2 and viral infectious disease: There are two signaling pathways to activate the host innate response against viral infection through production IFN-α and IFN-β; one is toll-like receptor (TLR)-mediated NF-κB, IFN regulatory factor-3 (IRF3), and IRF7 expression, and the other is RNA helicase retinoic acid-inducible gene I (RIG-I)-mediated mitochondrial antiviral signaling protein (MAVS) activation for activation of NF-κB and IRF3/726, 27.