CTLA4 and myocarditis: The gold-standard in the diagnosis of myocarditis remains the endomyocardial biopsy because it can provide evidence of the lymphocytic infiltrate, CD4 and CD* T cells, CD68 macrophages, rare CD20 cells and plasmocytes with no evidence of eosinophilic granulomas or giant cells (40, 41, 43, 44) because the mechanism is a direct injury by hiperactivated T cells (30).