The authors showed both in vitro and in vivo that overexpression of NDI1 reverses the antiproliferative and antitumoral action of metformin.29 As an energy disruptor, metformin has also been found to inhibit glucose production in hepatocytes30 and lipogenesis in prostate cancer.31 In response to the inhibition of complex 1 activity, cancer cells increase glucose consumption and glycolysis with an elevation of lactate production,28 decrease glucose oxidation and promote glutamine metabolism. The gene discussed is AVPR2; the disease is cancer.