Today's scientists are showing us how stem cells create and repair the human body. Unlocking these secrets has become the new Holy Grail of biomedical research. But behind that research lies a sharp divide, one that has continued for years, as using human embryonic stem cells is strongly opposed by many people. While stem cells offer the hope of creating or repairing tissues lost to age, disease, and injury, they also hold the potential to incite an international biological arms race. In this revised edition, the authors have included updated information on topics such as: Scientific advances with iPS cells; Clinical trials that are currently underway; hESC policy that is in the U.S. courts; Stem cells and biodefense; Developments at the California Institute for Regenerative Medicine and other research institutes around the world; as well as Growing international competition. It also covers all the basics of what stem cells are and how they work.