DMD and familial dilated cardiomyopathy: Interestingly, less common DCM variants in connecting proteins, such as dystrophin, which links the myofilament to the sarcolemma, or SR proteins (e.g., PLB, junctophilin), cause changes in myofilament function (e.g., reduced force, slow cross-bridge kinetics, changes in Ca2+ sensitivity) by activating intracellular pathways that target the myofilament with posttranslational modifications (phosphorylation, nitrosylation).