EIF2AK4 and viral infectious disease: Silencing of PERK eliminated the increase in eIF2α-P, contrary to silencing GCN2 (eIF2AK4) and PKR (eIF2AK2), the kinases that primarily respond to ribosome collisions, amino-acid starvation, and viral infection (Pakos-Zebrucka et al., 2016; Wu et al., 2020) (Fig. 1I–J).