Indeed, elevated miR-23b levels have previously been reported to induce cardiac hypertrophy, a phenotype observed in both CBK and CM-RevDKO hearts18,27,30,50,51 Interestingly, of the 19 putative miRNA targets that were induced both CBK and CM-RevDKO hearts, 16 are known to be regulated by let-7c-1-3p, thus highlighting the BMAL1–REV-ERBα/β–let-7c-1-3p relationship as a potential mechanism by which the circadian clock regulates cardiac processes. Here, BMAL1 is linked to cardiac hypertrophy.