Nuclear transfer and iPS may work best together.

A short meeting, held as an Arthur Sackler Colloquium of the United States National Academy of Sciences, was organized by Douglas Wallace, Susan Bryant, and Peter Donovan under the heading "Therapeutic Cloning: Where Do We Go from Here?" on October 8 and 9, 2007. The individual components required for therapeutic cloning now exist. The question, therefore, is what constraints presently limit or prevent its application to human therapy.