EIF2AK2 and viral infectious disease: Phosphorylation of eIF2α by PKR, PERK, and GCN2 has been reported to be associated with viral infection, but only PKR-mediated eIF2α phosphorylation was related to VACV infection (Jordan et al., 2002; Berlanga et al., 2006; Garcia et al., 2007; Backes et al., 2010; Sivan et al., 2018).