NOD2 and autoimmune myocarditis: It should be noted however that the NOD2 expression was not increased in patients with a persistence of the cardiotropic viruses parvovirus B19 or human herpesvirus 6 (HHV-6) type B, which are among the most frequently found cardiotropic viruses in endomyocardial biopsies24–26, whereas its regulation in primarily autoimmune myocarditis still needs to be investigated.