Sir Martin Evans, a British stem-cell scientist based at Cardiff University, has won the 2007 Nobel Prize for Medicine. Sir Martin, the first scientist to identify embryonic stem cells, was one of three scientists to share the prize for discovering "principles for introducing specific gene modifications in mice by the use of embryonic stem cells". He shares the £755,000 award with Mario Capecchi of the University of Utah and Oliver Smithies of the University of North Carolina.