In experimental studies, gene therapy has been shown to improve failing human myocardial function. The abnormal function of myocytes obtained from patients with dilated cardiomyopathy could be normalized by transfection of the myocytes in vitro with an adenovirus expressing the sarcoplasmic reticulum Ca2+-ATPase, SERCA2a; transfection increased Ca2+- ATPase activity 80 per cent. Some clinical studies have demonstrated the benefits of gene therapy and it appears to be a promising therapy.