A prior study on the expression profile of the mice heart reported that the differential expression of circSLC8A1, the most abundant circRNA in CMs, could act as an endogenous sponge for miR-133a and regulate the expression of miR-133a targets (serum response factor (Srf), connective tissue growth factor (Ctgf), adrenoceptor beta 1 (Adr β 1), and adenylate cyclase 6 (Adcy6)) in cardiac hypertrophy in vivo [28]. Here, SRF is linked to cardiac hypertrophy.