Thyroid hormone (TH) signaling is a relevant component of the adaptive response of the myocardium to stress, and plays a critical role in regulating both heart rate and contractility of myocytes: hyperthyroidism is correlated with atrial arrhythmias, hypertension, and heart failure, and increases the risk of heart failure and mortality in cardiopathic patients [13]. The gene discussed is TH; the disease is heart failure.