EIF2AK2 and viral infectious disease: Among the four well-known eIF2α kinases, PKR (the key cellular sensor of dsRNAs) also serves to induce the innate immune response through virus infection-induced production of type I IFNs which bind to an IFN-stimulated response element (ISRE) in the PKR promoter and activate PKR transcription (Kuhen and Samuel, 1997).