In the present study, we observed that FGF21 deletion significantly aggravated cardiac lipid accumulation (Fig.5), which was time-dependently associated with diabetes-accelerated cardiac dysfunction (Fig.2) and remodelling (Fig.3) in FGF21KO diabetic mice, indicating that FGF21 plays a critical role in cardiac protection from the development of DCM by regulation of cardiac lipid metabolism under type 1 diabetic conditions. This evidence concerns the gene FGF21 and familial dilated cardiomyopathy.