The Supreme Court will not review a challenge to federal funding of human embryonic stem-cell research, allowing the controversial studies to proceed.
The decision is a boon to supporters of stem-cell research, who believe it will yield treatments and cures for diseases such as Parkinson's and Alzheimer's.
The Association of American Medical Colleges (AAMC) applauded the court's decision not to review lower-court rulings that allow research to proceed at the National Institutes of Health.
"This is good news for patients. Research using hESCs conducted under rigorous ethical standards continues to offer great promise in the search for cures and treatments for a variety of intractable diseases," the AAMC said in a statement. "With the legislative, regulatory, and legal barriers cleared, we hope the promise of hESC research can now be realized."
Abortion-rights opponents, who equate research involving embryonic stem cells with murder, criticized the court's decision.
"Americans should not be forced to pay for experiments that destroy human life, have produced no real-world treatments, and violate federal law — especially in burdened fiscal times like these," said Steven Aden, senior counsel for The Alliance Defending Freedom (ADF), a Christian group that helped bring the case.
"Congress designed a law to ensure that Americans don’t pay any more precious taxpayer dollars for needless research made irrelevant by adult stem cell and other research. That law is clear, and we had hoped the U.S. Supreme Court would uphold its clear intent."
The challenge dismissed Monday was first brought in 2009 by James Sherley and Theresa Deisher, two researchers who work exclusively with adult stem cells.
Their suit prompted a federal judge to halt funding for embryonic stem cell research in 2010. That decision was blocked, then overturned by an appeals court.
In their ruling, appellate judges acknowledged ambiguity in laws governing stem-cell research, but ultimately deferred to the National Institutes of Health, which supports the studies.
Disputes over the ethics and legality of embryonic stem-cell research have lingered since the mid-1990s.