Lan et al. showed that cardiomyocytes (CMs) differentiated from hiPSCs derived from a hypertrophic cardiomyopathy (HCM) patient containing a gene mutation encoding for myosin heavy chain 7 (MYH7) retained the mutation and displayed the HCM phenotype, which is characterized by cellular hypertrophy and abnormal calcium handling activity as evidenced by irregular beating/arrhythmia [17]. The gene discussed is MYH7; the disease is hypertrophic cardiomyopathy.