The gold standard for diagnosing myocarditis is myocardial biopsy [10], which may demonstrate an intense, patchy lymphocytic infiltrate within the myocardium [9], that may also involve the cardiac sinus and atrioventricular nodes, positive for the T-cell marker CD3 or the macrophage marker CD68 [1,10-11]. The gene discussed is CD68; the disease is myocarditis.