It is important to understand the molecular mechanisms regulating energy expenditure in skeletal muscle cells. In particular, mitochondrial function and mitochondrial oxidative capacity has been a major research focus in the fight against obesity. This study was conducted under the hypothesis that the protein product of the c-Cbl gene negatively regulates the energy expenditure of muscle cells by inhibiting the mitochondrial capacity for oxidative function. It investigated the role played by the c-Cbl gene by examining c-Cbl gene knockout C2C12 cells for energy metabolism.