EIF2AK2 and viral infectious disease: Furthermore, eIF2α can also be phosphorylated by a heme-regulated translational inhibitor (Hri; also known as Eif2ak1)12,13 and protein kinase RNA-activated (Pkr; also known as Eif2ak2)14,15, which respectively respond to the heme deprivation and viral infection stresses, adding dimensions of complexity to these regulatory mechanisms.