EIF2AK2 and neoplasm: A variety of ISGs including the members of the IFN regulatory factor (IRF) family, dsRNA dependent protein kinase (PKR), 2–5A dependent RNase L (RNase L), TNF-related apoptosis-inducing ligand (TRAIL), promyelocytic leukemia gene (PML) and the death associated proteins (DAPs) exert their tumor suppressing functions through the induction of apoptosis in tumor cells [19].