MYLK3 and familial dilated cardiomyopathy: To examine whether other MYLK3 variants cause DCM, we first conducted targeted sequencing in our 52-patient unrelated DCM cohort and identified 15 patients (8 familial and 7 sporadic) with uncharacterized genetic etiology in known cardiomyopathy-related genes (Fig. 2, Supplementary Table 2).