After years of hearing scientists complain that the US federal government funded research on too few human embryonic stem cell lines, Lana Skirboll, who directs the Office of Science Policy at the US National Institutes of Health (NIH) in Bethesda, Maryland, has something to tell the stem cell community: "the ball is in their court". The NIH announced on 21 September that it would be accepting applications to determine whether a stem cell line is eligible for federal funding. The process is not without risks: some scientists are quietly concerned that their informed consent procedures could come under criticism or that they could lose access to nonfederal sources of funding if the lines they wish to work with aren't cleared by the NIH.

Some confusion over the process is already evident (see In the Field: Let the vetting begin). Scientists conducting research on a human embryonic stem cell (hESC) line should not submit it themselves, Skirboll says, but instead find out whether the group that derived the line will submit it. That's why the draft list is public, she says. "If you see a line that you're working on that has not been listed, you need to think about your research and talk to the deriver."

Geoff Lomax, who heads the standards group at the California Institute for Regenerative Medicine in San Francisco, suspects that the evaluation process could get extremely complex, particularly for older lines. One solution, he thinks, is to assess newer lines, which should more closely follow current thinking for informed consent requirements. Setting precedents soon would be useful, he says. "There's no need to deal with the hardest lines first."

"I hope like heck we have so many applications that we have that problem," says Skirboll. The first in-person meeting of the working group will not be scheduled until it's clear that there are enough lines to evaluate. "We're hoping that the order doesn't matter, that we can go through them very quickly."

The contents of the list have fluctuated in the few days it has been up. Some of the usual suspects are missing. As of 29 September, according to a draft list provided by the NIH, none of the hESC lines eligible for funding under the Bush administration has been submitted. (Spokesmen for University of Wisconsin have expressed an intention to add these lines.)

The NIH issued guidelines in July that included strict criteria for documenting informed consent (see US stem-cell research expands). Lines created after July will undergo a simple administrative review for strict compliance with the guidelines. But the more frequently studied hESC lines derived prior to the guidelines will need to be evaluated individually by an NIH working group to see if they are consistent with the spirit of the guidelines. Though lines that do not pass muster with the NIH can still receive research funding from private organizations and individual states, the deliberations of the NIH working group will be made public, and thus granting agencies may be reluctant to award funds to material that lacks NIH approval.

Moreover, the evaluation will require universities to submit sensitive material. Any documentation containing personally identifiable information about donors will not be retained by the NIH, says Skirboll, and though consent forms and other documentation will not be made public, she says, it will be subject to the Freedom of Information Act.

Institutions have legitimate worries about public overreaction and the disclosure of proprietary information, says Robert Streiffer, a bioethicist at the University of Wisconsin–Madison who has raised concerns about the informed consent standards applied to funding hESC lines under the Bush administration (see When the past catches up with the present). Nonetheless, he says, "if you're not willing to publicly disclose the conditions under which you derived your cells, that's a pretty big red flag".

With the exception of two lines from biotech company BresaGen, Streiffer thinks lines eligible for funding under President Bush will also be deemed eligible for funding under the Obama administration.

The more interesting question, Streiffer says, is whether the NIH will seek to enforce consent criteria unique to particular lines. For example, he says, hESCs cannot be mixed into human embryos under the Obama guidelines, but consent forms from the University of Wisconsin–Madison state that cells cannot be mixed with any sort of embryo.

Skirboll says that specific consent conditions will be posted along with the lists of lines eligible for federal funding, and that grant applications proposing experiments outside these conditions will not be eligible for funding.