From Embryo to Stem Cell

Stay Connected with TIME.com

• Subscribe to
  RSS Feeds
• Sign Up for
  Newsletters
• Get the TIME
  Magazine iPad Edition
• Read TIME Mobile
  on your Phone
• Become a
  Fan of TIME
• Get TIME
  Twitter Updates

• NewsFeed
• U.S.
• Politics
• World
• Business
• Health
• Science
• Entertainment
• Style
• Photos
• Videos
• Specials
• Magazine

• Privacy Policy
• Your California Privacy Rights
• RSS
• Newsletter
• Mobile
• TIME For Kids

• Subscribe
• Contact Us
• Terms of Use
• Media Kit
• Reprints & Permissions
• Help
• Site Map
• Ad Choices
• Custom Content