Tenascin-C is a large extracellular glycoprotein that is only expressed during embryonic development, and not in the normal adult heart.[22] However, with exposure to inflammatory stress, it reappears in the heart in, for instance, myocardial infarction and myocarditis.[23] Recently, the close association between tenascin-C and inflammation has been uncovered. The gene discussed is TNC; the disease is myocarditis.