CAPN1 and diabetic cardiomyopathy: This study aimed to determine whether the same mechanism underlies its protective effect against diabetic cardiomyopathy (DCM).<h4>Methods</h4>At the <i>in vivo</i> level, calpain-1 knockout mice with the genotype Capn1 EK684-/- (Capn1 EK684 knockout mice) were used to establish a type 2 diabetic cardiomyopathy model.