Stem cells can be employed to replace damaged and diseased cells, curing many diseases. As scientists pursue research into stem cells, they have unlocked many secrets about how cells form and how they affect the body. This title examines the science behind stem cell research in the following chapters: What Are Stem Cells? The Mysteries of Embryonic Stem Cells, Rebuilding Damaged Bodies with Adult Stem Cells, Therapeutic Cloning: Altering the DNA of Stem Cells, New Advancements, New Challenges.