CD4 and myocarditis: In contrast to the well-defined cardiac antigen-specific T-cell responses, our understanding of the role of heart non-specific CD4+ T cells in myocarditis is limited. Recently, Zarak-Crnkovic et al. (36) demonstrated in a proof-of-concept study that heart non-specific effector T cells did not affect the severity of myocarditis, but protected the heart from adverse post-inflammatory fibrotic remodeling and cardiac dysfunction in the chronic stage.