Mammalian cells encode four eIF2α kinases, the protein kinase R (PKR), the heme-regulated inhibitor (HRI), the general control non-derepressible protein 2 (GCN2), and the PKR-like endoplasmic reticulum kinase (PERK), which are activated in response to heat shock, amino acid deprivation, ER stress or viral infection, preventing eIF2 recycling by eIF2B. The gene discussed is EIF2AK2; the disease is viral infectious disease.