Autoimmunity is considered to play an important role in myocarditis, while also contributing to the progression to dilated cardiomyopathy and heart failure.The role ofT-helper (Th) cells is thought to be crucial in autoimmune diseases.Although the Th cells identified by functions as various Th subsets secreting distinct cytokine patterns, it is difficult to understand the development of myocarditis based on the usual Th subset paradigm such as Thl/Th2.Suppressor of cytokine signaling (SOCS) inhibits the eytokine signaling pathways in both innate and adaptive immunity.In the present study, we have examined the effect ofplasmid DNA encoding SOCS 1 or SOCS 1 antagonist (dominant negative;SOCSIDN) in experimental autoimmune myocarditis (EAM) induced by α-myosin-heavy chain peptide (MyHC-α)immunization.