The full spectrum of T cell-mediated myocardial inflammation, ranging from acute myocarditis and chronic inflammatory cardiomyopathy to heart failure, can be recapitulated in T cell receptor transgenic mice with more than 95% of the CD4+ T cell pool recognizing the immunodominant MYH6614–629 epitope (TCRM mice)7,30. Here, CD4 is linked to acute myocarditis.