TYK2 and viral infectious disease: Thus, upon detection of (ds)RNAs by specific host protein sensors and upregulation of type I interferon levels, the secreted IFN-I (IFN-α and IFN-β) binds to the IFN receptors (IFNARs) on the surface of the infected and neighboring cells in a paracrine or autocrine manner [31,32] thus commuting the signal of virus-infection, by activating the Janus kinase 1 (JAK1) and tyrosine kinase 2 (TYK2), which in turn phosphorylate the signal transducer and activator of transcription proteins 1 and 2 (STAT1 and STAT2) [33].