In a mouse model of CD8+ T cell-mediated myocarditis, WT CTLs were transferred into PD-L1/2−/− recipient mice and WT-bone marrow PD-L1/2−/− chimeras, both models suffered lethal myocarditis with severe cardiac inflammation and cardiac immune infiltration compared with control WT recipients. The gene discussed is CD8A; the disease is myocarditis.