NKX2.5, an early marker of pre-cardiac mesoderm and cardiac progenitors, was significantly decreased in the patients compared to the control DCM-C- iPSCs-CMs (3.5 fold for DCM-O-iPSCs-CMs and fivefold for DCM-R-iPSCs-CMs, p < 0.001, Fig. 3A). This evidence concerns the gene NKX2-5 and familial dilated cardiomyopathy.