Publisher's Synopsis
Human embryonic stem cells hold great interest because of their pluripotency-their capacity to give rise to the various specialized cells of the body-and because of their longevity-their ability to be propagated for many generations in laboratory culture without losing their pluripotency. Until now, these cells have been obtainable only from living human embryos [at the 100-to-200-cell (blastocyst) stage of development] by a process that necessarily destroys the embryos and that therefore makes this research ethically controversial. Over the past several years, the ethical controversy has been the subject of federal (and state) legislation and public policy and of ongoing public debate.
