α-MHC719/+ mice displayed all pathognomonic features of HCM, like myocardial hypertrophy in transthoracic echocardiography (Fig. 4A,B, Supplement Fig. 6 and Supplement Table 1) and increased disordered relaxed state (DRX) of the myosin filaments (Fig. 4C) as previously described. The gene discussed is MYH14; the disease is cardiac hypertrophy.