Three years ago, when Rene Rejo Pera was setting up a new lab at the University of California, San Francisco (UCSF), she had to make sure she had two of everything: one microscope for her federally funded lab, for example, and one for a privately funded replica next door. Because of funding restrictions on stem-cell research ordered by President George W. Bush in 2001, this was a redundant scenario played out in labs across the country. The edict specifically limited federal funding for embryonic stem-cell research to a small number of cell lines already in existence, leaving scientists who wanted to conduct cutting-edge research in this area scrambling for private money.

Scientists are now looking forward to an end of that edict. President Barack Obama promised during his campaign to overturn the order, and most expect the action to happen soon. "The imminent change in policy will quite literally allow us to take down these walls and integrate the laboratories in a way that will make the work move much more efficiently," says Arnold Kriegstein, director of the Broad Center of Regeneration Medicine and Stem Cell Research at UCSF.

The new policy is expected to mean that scientists will have unfettered access to newer, better embryonic stem cells, which will speed the pace of research. Even without funding restrictions, however, scientists receiving government grants could not use that money to generate new lines, which requires the destruction of an embryo. Kriegstein and others hope that the change will bring a new sense of legitimacy to an often embattled field, as well as return a leadership role to the National Institutes of Health (NIH), the nation's premier biomedical funding agency, in one of the most promising areas of biomedical research. Much of the research has shifted to institutes funded by state initiatives, such as the California Institute for Regenerative Medicine, or by private donors. In addition to limiting funding, "the other reality of [the Bush] policy is all the negative publicity it has created," says Tim Kamp, codirector of the Stem Cell and Regenerative Medicine Center at the University of Wisconsin. "Frankly, I think it did greater damage than funding restrictions, [in] that it scared many researchers away."

Despite the restrictions, U.S. scientists have employed embryonic stem cells for a broad range of research. Because the cells can develop into any tissue type, scientists are coming up with ways to prod them to differentiate into brain cells, heart cells, and other cell types, both to better understand the diseases that strike these tissues and to potentially create replacement tissue for therapies. But much of the most promising research has moved overseas.

Once the restriction is lifted, labs funded by federal dollars will be allowed to use most of the estimated 600 stem-cell lines that have been created around the globe. Researchers broadly agree that the newer lines, which were derived using more refined methods, are superior to the older ones. Using only the old lines is like "being required to use Microsoft Word 1998," says Jeanne Loring, director of the Center for Regenerative Medicine at the Scripps Research Institute, in La Jolla, CA.

In addition, the earlier lines were derived using animal products, making them largely unfit for therapeutic use. "There are hundreds of embryonic stem-cell lines out there that have been made under the best conditions, and some of them are patient ready," says John Gearhart, director of the Institute for Regenerative Medicine at the University of Pennsylvania, in Philadelphia. "They have greater utility, performance, and safety than [the Bush-approved] lines."