CII has been suggested to regulate cellular energy metabolism in scenarios such as cancer, diabetes, and inflammation due to its bidirectional interconversion of succinate to fumarate by the peripheral membrane catalytic subunit SDHA and ubiquinone (CoQ10) to ubiquinol (CoQ10H2) interconversion at a reaction site formed by membrane subunits SDHC and SDHD (1–5). This evidence concerns the gene SDHA and cancer.