Since the phenotype and FGF21 level are different in two types of diabetes-induced cardiomyopathy26, it is unreasonable to predict the effect of FGF21 on T2DM-induced cardiomyopathy just based on the antiapoptotic effect of FGF21 in the hearts of mice at the early stage of T1DM. Here, FGF21 is linked to type 1 diabetes mellitus.