ISR can be triggered by various insults including deprivation of amino acids or heme, ER stress, and viral infections, each of which activates one of the four eukaryotic translation initiation factor 2α (eIF2α) kinases, GCN2, heme-regulated inhibitor (HRI) kinase, PERK, and PKR respectively, leading to the phosphorylation of eIF2α, encoded by the EIF2S1 gene (Pakos-Zebrucka et al., 2016). This evidence concerns the gene EIF2A and viral infectious disease.