EIF2A and infection: Fig. 5A and B), but the impact was significant only in omicron-infected cells (Fig. 5A and B). ISRIB treatment also reduced SG formation at 6 hpi (Suppl. Fig. 5C), indicating that the ISR plays a role in formation of SGs and triggering translational shutdown at early stages of infection. In uninfected cells treated with sodium arsenite, translational levels were only partly restored. Sodium arsenite highly activates the ISR, possibly exceeding the threshold of eIF2α-phosphorylation which ISRIB can counter (Rabouw et al., 2019).