Scientists at Newcastle University in England create the first ever artificial liver cells using umbilical cord blood stem cells in October 2006. It is suggested that these stem cells have the ability to differentiate into more cell types than adult stem cells, opening up greater possibilities for cell-based therapies. Then, in early 2007, researchers led by Dr. Anthony Atala claimed that a new type of stem cells had been isolated in amniotic fluid. This finding is particularly important because these stem cells could prove to be a viable alternative to the controversial use of embryonic stem cells. Mario Capecchi, Martin Evans, and Oliver Smithies won the 2007 Nobel Prize for Physiology or Medicine for their work on embryonic stem cells from mice using gene targeting strategies producing genetically engineered mice (known as knockout mice) for gene research.