Endomyocardial biopsy. As regards EMB in addition to the Dallas histological criteria based on hematoxylin-eosin staining [82], immunohistochemical staining is used to identify CD3+ T cells and CD68+ macrophages, which are necessary to identify specific histological subtypes of myocarditis and differentiate them from phenocopies [47,83]. This evidence concerns the gene CD68 and myocarditis.