EIF2AK2 and viral infectious disease: Host innate immune responses to virus infections are initiated by the detection of viral pathogen-associated molecular patterns (PAMPs) (e.g. CpG-DNA, dsRNA, uncapped ssRNA with 5′ triphosphate or specific viral proteins) by cellular pathogen recognition receptors (PRRs) (e.g. Toll-like receptors (TLRs), retinoic acid inducible gene I protein (RIG-I), melanoma differentiation antigen 5 (mda-5) and protein kinase R (PKR)) located on the plasma membrane, in the endosomal compartment or within the cytoplasm of infected cells (reviewed in [1], [2]).