Following an outcry from the Obama administration and the scientific community, an appeals court Thursday lifted the controversial Aug. 23 injunction placed on federal funding for human embryonic stem cell research by Judge Royce C. Lamberth.
Fearing the temporary injunction would set back valuable research on difficult-to-treat illnesses such as Parkinson's disease, the Obama administration had issued an emergency request to Lamberth to lift the ban until matters were settled in court on Sept. 1.
Standing behind his original ruling, the judge rejected the request earlier this week, leaving supporters of the research little room to hope for a timely reversal of the ban.
In a surprising turn of events however, a three-judge panel of the U.S. Circuit Court of Appeals for the District of Columbia granted a request from the Justice Department to stay the funding ban, saying that the Obama administration could resume funding the research while a full appeal of the case is processed.
Though research can resume for the time being, the fate of human embryonic stem cell research is still very much in the air, scientists said.
"It's hard for researchers to know how to plan for the future," said Timothy Kamp, a University of Wisconsin researcher who has been focusing on embryonic stem cells in heart disease. "This is obviously a temporary change in the tides and we will be hesitant to initiate new projects using human embryonic stem cells until this is sorted out.
"We're obviously delighted that the injunction is lifted, but there are enough legal questions with the existing structure of the law that there is potential for the appeal to not be successful," he added.
Other scientists were more hopeful.
Doug Melton, co-director of the Harvard Stem Cell Institute, said in a prepared statement that the development was "terrific news."
"I realize that this is a temporary order, but I am hopeful that the Court of Appeals understands the enormous potential this research holds, it's promise for millions of patients, and will allow regular funding of the work to resume," he said.
The temporary injunction was put in place this August when Lamberth ruled in favor of a case brought by Christian medical groups and adult stem cell researchers against the federal government's ongoing funding of research involving human embryonic stem cells.
The plaintiffs argued that the expanded use of these cells sanctioned by a 2009 executive order from the Obama administration violated the 1995 Dickey Wicker amendment that prohibited federally funded research in which a human embryo is "destroyed, discarded or knowingly subject of risk of injury or death."
Research condoned by the 2009 executive order follows strict ethical guidelines put in place by the National Health Institutes and no federal funding goes to the actual destruction or creation of human embryonic stem cells. But stem cells already created by other sources are available for use by government-funded projects -- the main point of contention for the plaintiffs.
"The Obama administration tried to say that if private funding was used to create and destroy embryos, federal funding could be used for the research, but it's all part of the same process," said Ron Stoddart, executive director of Nightlight Christian Adoptions, an agency that was one of the original plaintiffs in the lawsuit.
The agency organizes adoptions of unused stem cells created during in vitro fertilization so that these potential fetuses can be given to infertile couples.
Though Lamberth wrote in his ruling that he believed he was preserving the "status quo," the scientific community was shocked by the decision and lamented the breadth of impact it could have.
Dr. Francis Collins, director of the National Health Institutes, told reporters in a telephone briefing that "this decision has the potential to do serious damage to one of the most promising areas of biomedical research. It comes just at the time when we were really gaining momentum."
Cause and Effect, What a Ban Can Do
Susan Solomon, CEO of New York Stem Cell Foundation, told ABC News following the injunction that a ban has the potential to interfere not only with all federally funded research involving embryonic stem cells, but with many privately-funded labs and projects as well.
"This will stop research all over the country. Even if you have private funding, there's an impact because many of your collaborators could be federally funded and affected by this ruling," she said.
The NIH's consideration of future grants for this kind of research was initially blocked by the injunction. However, the NIH announced shortly after the ruling that projects in process would be able to continue.
Now that the injunction is temporarily lifted, grant consideration can theoretically resume, though the potential for the appeal to fail in court continues to loom over research, scientists said.
The fact that the injunction was ruled in the first place, and eventually could stand, highlights the danger of having medical research policy that is subject to the whims of the judicial system, Solomon said.
Now researchers are hoping for a lasting legislative change that will end the "on again, off again" of scientists' legal right to funding once and for all, Kamp said.
"Human embryonic stem cells have stood the test of time and are the current gold standard for human master stem cells. Losing the ability to compare other stem cells to this gold standard puts federally funded investigators at a scientific disadvantage," he told ABC News. "Overall, U.S. researchers will be at a competitive disadvantage compared to others in many parts of the world."