This latest volume in Springer's Stem Cell Biology and Regenerative Medicine series looks at the state-of-the-science in stem cells, discusses the current challenges, and examines the new directions the field is taking. Dr. Turksen, Editor-in-Chief of the journal Stem Cell Reviews and Reports, has assembled a volume of internationally-known scientists who cover topics that are both research and clinically oriented. The contents range from sources of stem cells through their physiological role in health and disease, therapeutic applications in regenerative medicine and ethics and society. An initial overview and a final summary bookend the contents into a cohesive and invaluable volume.