In this study, we successfully established BMAL1 KO hESC cell lines and derived human BMAL1-deficient cardiomyocytes to mimic heart disorders associated with circadian malfunction (Young et al., 2001; Takeda and Maemura, 2010; Alibhai et al., 2017; Alibhai et al., 2018). This evidence concerns the gene BMAL1 and heart disorder.