Tropomyosin is an actin-binding protein that regulates actin mechanics. Tropomyosin is important, among other things, for muscle contraction. Tropomyosin, along with the troponin comple, Xenopus/Amphibian,, associates with actin in muscle fibers and regulates muscle contraction by regulating the binding of myosin. Defects in tropomyosin are the cause of cardiomyopathy familial hypertrophic type 3 (CMH3). Familial hypertrophic cardiomyopathy is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum.