Both the head-head and the coiled-coil/BH interfaces involve part of a large and flat surface of myosin heads called the Mesa (Fig. 3a; Supplementary Fig. 7), which was originally defined as a large and relatively flat surface of the myosin head containing highly conserved residues among β-cardiac myosins across species, which are hot-spots for cardiomyopathy mutations21. Here, MYH14 is linked to cardiomyopathy.