Myocarditis is an inflammatory condition in the myocardium that is histopathologically defined by inflammatory cell infiltration adjacent to cardiomyocytes and is classified as follows based on the predominant type of infiltrating cell: lymphocytic, eosinophilic, giant cell, or granulomatous [112].Lymphocytic myocarditis is the most common type and is characterized by the predominant infiltration of CD4- and CD8-positive T lymphocytes associated with CD68-positive macrophages [113]. This evidence concerns the gene CD4 and myocarditis.