EIF2AK1 and viral infectious disease: Four eIF2α kinases are involved in eIF2α phosphorylation: PERK, double-stranded RNA protein kinase R (PKR), heme-regulated inhibitor kinase (HRI) and general control non-derepressible-2 (GCN2), which are activated to respond to the accumulation of unfolded proteins, the presence of double-stranded RNA during viral infection, heme deficiency and amino acid starvation, respectively [3, 8].