 As part of the ubiquitin–proteasome system (UPS), the proteasome maintains cardiac protein homeostasis and thus plays a significant role in cardiac ischemic injury, ventricular hypertrophy and heart failure.Additionally, evidence is accumulating that the UPS plays an essential role in malignant transformation.UPS proteolysis plays a major role in responses of cancer cells to stimulatory signals that are critical for the development of cancer.