CAV3 and cardiomyopathy: Furthermore, Cav-3 null mice show not only loss of caveolae, but also abnormalities in T-tub system organization (in skeletal muscle), such as dilatation and loss of transverse orientation (12), and Cav-1/Cav-3 double-knockout mice show complete loss of cardiac caveolae, T-tub disorganization, and severe cardiomyopathy (12, 14).