MYH14 and familial dilated cardiomyopathy: Interestingly, the opposite was recently reported for two dilated cardiomyopathy (DCM) associated mutations, E525K in the heavy chain (Rasicci et al, 2022; Duno-Miranda et al, 2024) and D94A in the RLC (Yuan et al, 2022), both of which show an increase in SRX, and the assumed decrease in the number of myosin heads available for force production is proposed to be the primary mechanism of hypocontractility associated with these mutations.