EIF2AK3 and infection: Interestingly, even though PERK was autophosphorylated in response to Tunicamycin (TM), an ER stress inducer, in both mock-infected and RV-SA11-infected cells, TM treatment could not result in stabilization of Nrf2/HO-1 proteins during RV-SA11 infection (9 hpi) (Figure 5(g)).