EIF2AK3 and severe acute respiratory syndrome: Abbreviations: SARS-CoV, Severe Acute Respiratory Syndrome-Coronavirus; PLpro, Papain-like protease; 3CLpro, 3C-like protease; nsp, non-structural protein; RTC, replicase-transcriptase complex; HMOX1, Heme oxygenase 1; PERK, PKR-like ER kinase.