Interestingly, we found that a number of genes that play an essential role in regulating apoptosis, such as CASP3, CASP8, CASP9 and XIAP, genes controlling CM contractility, such as MYL2, MYL3, α-actinin (ACTN1) and α-tropomyocin (TPM1), and genes involved in heart diseases, such as MAPK11, COL3A1 and CALM1, were abnormally expressed in DMD-iPS1 CMs when compared with control S3 iPSC-CMs (Fig. 3A). Here, DMD is linked to heart disorder.