The Mitochondrial Pyruvate Carrier (MPC) conducts pyruvate from the cytosol into the mitochondrial matrix. The import of pyruvate into mitochondria is a critical metabolic decision because it links glycolysis, which does not require oxygen, with mitochondrial oxidative phosphorylation. Recent evidence demonstrates that mitochondrial pyruvate carrier (MPC) function is abnormal in some cancers and that increasing MPC activity may decrease cancer proliferation.