CTLA4 and myocarditis: The important role of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) has already been suggested 25 years ago in a CTLA-4 deficient mouse strain with the development of lymphoproliferative disease with multiorgan lymphocytic infiltration and tissue destruction, with particularly severe myocarditis and pancreatitis, and death after 3–4 weeks of age.