KCNJ2 and Duchenne muscular dystrophy: To confirm whether this phenomenon occurs in both hemizygous and heterozygous DMD iPSC-CMs, we analyzed the mRNA levels, and protein expression of the cardiac ion channels NaV1.5 (encoded by SCN5A gene), Kir2.1 (encoded by KCNJ2 gene), and CaV1.2 (encoded by CACNA1C gene).