EIF2AK1 and viral infectious disease: Specifically, there are four kinases in mammalian cells, namely general control nonderepressible 2 (GCN2), double-stranded RNA-dependent protein kinase (PKR), heme-regulated inhibitor (HRI) and PKR-like endoplasmic reticulum kinase (PERK), which sense amino acid depletion, viral infection, heme deficiency and endoplasmic reticulum (ER) stress respectively (Ebert et al., 2022; Yan et al., 2024).