Hematopoietic stem cells (HSCs) not only renew themselves by dividing but also differentiate to form all of the body’s blood cells. But the mechanisms that keep HSC division and differentiation in balance remain unclear. Keisuke Ito, M.D., Ph.D., has received a five-year, $2.9 million grant to find the factors that determine the fate of HSCs. After transplanting HSCs into a mouse model, Dr. Ito and his colleagues will isolate and analyze individual HSCs to determine which fate they have chosen—division or differentiation—and what cellular factors caused them to make that choice. Findings from this study could, for example, allow scientists to manipulate HSCs so that they differentiate into blood for use in transfusions. Dr. Ito is associate professor of cell biology and of medicine and director of scientific resources at the Gottesman Institute for Stem Cell and Regenerative Medicine Research. (1R01DK115577)