Because the PERK inhibitor GSK2656157 disrupts the interaction of TRIM29 and phosphorylated PERK, reduces PERK-mediated ER stress and apoptosis, abolishes TRIM29-induced PERK SUMOylation and restricts replication of the cardiotropic viruses CVB3 and EMCV in vitro, we next investigated whether the PERK inhibitor GSK2656157 treated viral myocarditis in a wild-type mouse model of CVB3-induced myocarditis in vivo. The gene discussed is TRIM29; the disease is myocarditis.