BioEd Online

Colorado congresswoman Diana DeGette had one message for President Barack Obama when she shook his hand on 17 February, moments after he signed the massive US economic stimulus bill into law. "I just looked at him and said: 'Mr President, just to reiterate my hope that you will sign an executive order reversing President Bush's ban on [human] embryonic stem-cell research'," says DeGette (Democrat). "He said: 'We're gonna do it soon.'"

Those words, and others like them from Obama, are doing less and less to placate backers of federal funding for stem-cell research. During his campaign, Obama promised to reverse President George W. Bush's 2001 policy that strictly limited federal funding for the research. Many expected it to be one of Obama's first moves, mirroring President Bill Clinton's lifting of the moratorium on fetal tissue transplantation research just after taking office in 1993.

"Obviously, we have concerns and would like to see this done," says Tony Mazzaschi, interim chief scientific officer at the Association of American Medical Colleges based in Washington DC and a board member at the Coalition for the Advancement of Medical Research (CAMR, also Washington-based), an umbrella group of associations that back federal funding for the research. "All of us have been getting pressure from our constituents: 'When is this going to happen? Is everything okay?'"

On 6 February, CAMR wrote to Obama saying it was "concerned" about media reports that presidential action was being delayed to coincide with congressional legislation. On 4 February, DeGette, together with Michael Castle (Republican, Delaware), introduced such legislation, which would explicitly permit federal funding for research on stem-cell lines derived with parental permission from embryos left over at fertility clinics and otherwise slated for destruction. And on 18 February, six Republican members of Congress led by Castle wrote to Obama to "urge that you immediately lift the current federal restrictions on funding for embryonic stem cell research".

The White House has been by turns affirming and evasive. Senior presidential adviser David Axelrod, when asked on Fox News Sunday on 15 February when the president would enact an executive order, replied only that Obama is "considering" such a move. White House spokesman Shin Inouye told Nature last week: "President Obama is committed to providing federal support to stem-cell research. His administration will be acting soon to lift the previous restrictions on this important effort."

Some Washington insiders suggest that there is no more to the delay than a president consumed by a major economic crisis. Others note that the new administration had (at the time Nature went to press) yet to install a National Institutes of Health (NIH) director or secretary of health and human services — key people the president will need to rely on to enact an executive order and serve as the public face of the administration on a controversial issue.

Yet others contend that Obama's lack of action five weeks into his presidency highlights the complexity of the legal issues involved in reversing the Bush ban, which limited federal funding for stem-cell research to a score of lines derived before 9 August 2001.

Louis Guenin, a lecturer on ethics at Harvard Medical School in Cambridge, Massachusetts, believes that an Obama executive order could be successfully challenged in court in the absence of enacted legislation explicitly approving federal funding for stem-cell research. That, he says, is because of the Dickey–Wicker amendment: a law first enacted by Congress in 1995 and renewed each year since, which prohibits US funding of research in which embryos are created or destroyed.

"Anyone concerned about complicity in embryo destruction is keen to spot collaboration, inducement, or artifices to mask them," says Guenin. "In view of congressional intent to prevent taxpayer complicity, 'research in which a human embryo or embryos are destroyed' captures any project whose demand for materials induces embryo destruction."

Other legal scholars disagree with Guenin, and point to a 1999 legal opinion by Harriet Rabb, then the general counsel at the Department of Health and Human Services, which concluded that federal funding for stem-cell research does not contravene Dickey–Wicker because the cells themselves are not embryos and research on already derived cells does not destroy embryos. The Rabb opinion has never been tested in court.

Guenin has caught the ear of some key scientists, including John Gearhart, director of the Institute for Regenerative Medicine at the University of Pennsylvania in Philadelphia. During the presidential transition, Gearhart forwarded a 29-page Guenin memo to Harold Varmus, a former NIH director and a leading member of the Obama transition team. "I am concerned that an executive order is not sufficient to prevent what happened during the Bush administration on stem-cell research," says Gearhart.

Varmus was out of the country and did not respond to an e-mail asking for comment.

George Daley, the associate director of the Stem Cell Program at the Children's Hospital, Boston, passed the same memo to Alta Charo, a professor of law at the University of Wisconsin, Madison, and another transition-team member. "I think it's an important issue to vet," says Daley. "We want to make sure we do have all the possible legal rights to get funding."

Charo said that her role on the transition team prevented her from commenting.

DeGette, for her part, argues that legislation is needed — but not to subvert court challenges. She wants to prevent Obama's successor from reversing an Obama executive order. "My main concern is that the whole issue of embryonic stem-cell research does not become a ping-pong ball," she says.