Studies in cancer cells have shown that the physical interaction of human Esrra with Ppargc1a strongly enhances the binding of Esrra to DNA to induce the activation of the targeted genes (Schreiber et al., 2003), including Mpc1, responsible for the import of cytosolic pyruvate into mitochondria and PDH, that catalyzes the conversion of pyruvate to acetyl-CoA in mitochondria. The gene discussed is PDP1; the disease is cancer.