CAP2 and cardiomyopathy: Indeed, recent studies identified CAP2 as a crucial regulator of myofibril differentiation in both skeletal and cardiac muscles [12,13], and they reported a cardiomyopathy associated with dilated ventricles and impaired heart physiology as well as impaired skeletal muscle development for systemic CAP2 knockout (CAP2-KO) mice [12,14,15,16,17].