This chapter contains sections titled: Normal Mitochondria Morphological Defects in Tumor Cell Mitochondria Proteomic Abnormalities in Tumor Cell Mitochondria Lipidomic Abnormalities in Tumor Cell Mitochondria Cardiolipin: A Mitochondrial-Specific Lipid Cardiolipin and Abnormal Energy Metabolism in Tumor Cells Complicating Influence of the In Vitro Growth Environment on Cardiolipin Composition and Energy Metabolism Mitochondrial Uncoupling and Cancer Cancer Cell Heat Production and Uncoupled Mitochondria Personal Perspective Summary References