CTRL and familial dilated cardiomyopathy: No significant differences in the activity of the chymotrypsin-like (control: 1.00 ± 0.06 μU/mg, ICM: 0.90 ± 0.14 μU/mg, DCM: 1.02 ± 0.07 μU/mg, p = 0.71) (Figure 1A) or caspase-like (control: 0.06 ± 0.85 μU/mg, ICM: 0.18 ± 0.73 μU/mg, DCM: 0.19 ± 0.70 μU/mg, p = 0.93) domains of the proteasome were observed in myocardial tissue from ICM, DCM, and control patients.