CAV3 and heart failure: Cav-3 likely plays a role in the localization of the β2-adrenoceptor to the t-tubule so that the loss of Cav-3 regulation from the t-tubule membrane in heart failure contributes directly to the redistribution of the receptor to the surface sarcolemma and the loss of localization of β2-adrenoceptor signaling to the t-tubule in failing myocytes (1, 5, 27, 32).