Such methods, however, are unlikely to resolve the ethical debate because, in the eyes of some, they still endanger embryos. Grompe's approach holds out the promise of unraveling the moral dilemma. If it works, no embryo will have been produced -- so no potential life will be harmed. As a result, some conservative ethicists have endorsed Grompe's proposal.

Whether it is actually a feasible way to harvest embryonic stem cells remains uncertain. Some are skeptical. "There's really no evidence it would work," says Jaenisch. "I doubt it would." But the experiments Grompe proposes, Jaenisch says, would still be scientifically valuable in helping explain how to reprogram cells to create stem cells. Harvard Stem Cell Institute scientist George Daley agrees. In fact, Daley's lab is also studying nanog's ability to reprogram adult cells.

Still, many biologists and bioethicists have mixed feelings about efforts to reprogram adult cells to become pluripotent. While they agree the research is important, they worry that framing it as a search for a stem cell compromise may slow funding -- private and public -- for embryonic-stem-cell research, hampering efforts to decipher or even cure diseases that affect thousands of desperate people. Such delays, they argue, are a greater moral wrong than the loss of cells that hold only the potential for life.

Many ethicists -- and the majority of Americans -- seem to agree. "We've already decided as a society that it's perfectly okay to create and destroy embryos to help infertile couples to have babies. It seems incredible to me that we could say that that's a legitimate thing to do, but we can't do the same thing to help fight diseases that kill children," says David Magnus, director of the Stanford Center for Biomedical Ethics.

OTHER PLAYERS
Nuclear Reprogramming

George Daley -- Studying nanog's ability to reprogram nuclei
Harvard Medical School

Kevin Eggan -- Reprogramming adult cells using stem cells
Harvard University

Rudolf Jaenisch -- Creating tailored stem cells using altered nuclear transfer (CDX2)
MIT

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