Raul Mostoslavsky, MD, PhD, is a principal investigator at the Mass General Center for Cancer Research and assistant professor at Harvard Medical School. His research laboratory has made important discoveries relating to a newly discovered class of genes called sirtuins, which has been linked to aging, metabolism and cancer. In a landmark discovery, Dr. Mostoslavsky’s laboratory discovered that the sirtuin gene SIRT6 is activated under conditions of oxygen and nutrient stress (as observed in tumors) and directly regulates the metabolism of glucose. This finding helps explain some fundamental observations about the different metabolism of cancer cells, which are known to use glucose for energy in very different ways from normal human tissues. The generally altered metabolism of cancer cells provides one of the most exciting new avenues in cancer research, with important implications for targeting cancer cells with high specificity.