EIF2AK1 and infection: There are four known kinases that phosphorylate eIF2ɑ in response to various physiological or environmental stresses: PKR-like ER kinase (PERK) is activated downstream of ER stress; general control non-derepressible 2 (GCN2) is responsive to amino acid deprivation; protein kinase RNA-activated (PKR) senses infection-derived dsRNA; and heme-regulated inhibitor (HRI) binds hemin and is disinhibited upon cellular heme deficiency.