U ncertainty over federal funding for human embryonic stem cell research gained a temporary reprieve recently as a panel of federal appeals court judges ruled 2 – 1 to overturn a preliminary injunction. But the legal issue of whether the National Institutes of Health violated the 15-year-old Dickey – Wicker law, which prohibits using taxpayer dollars for research that destroys or harms human embryos, moved back to the lower court and Chief Judge Royce C. Lamberth for a decision. Lamberth, a judge in the Federal District Court in Washington, imposed the ban last year, briefl y disrupting intramural research on these earliest human cells on the NIH Bethesda campus, as well as grants to medical schools across the country. “Now the action turns to the main event, the merits of the case,” said Anthony Mazzaschi, senior director of scientifi c affairs for the Association of American Medical Colleges, referring to Sherley v. Sebelius . Lamberth gave both sides in the legal action until June 24 to fi le supplemental briefs before he issues a fi nal summary judgment. When that might come is uncertain, although Mazzaschi said he hopes it will happen within the next 6 weeks. No matter which side prevails, the government or the two scientists — researchers using adult stem cells and who sued the government in August 2009 — the case eventually could come before the U.S. Supreme Court. The scientists, James Sherley, M.D., Ph.D., of the Boston Biomedical Research Institute, and Theresa Deisher, Ph.D., of AVM Biotechnology, won the right to sue on the basis of their claim that adult stem cell research was at a competitive disadvantage to embryonic stem cells for NIH research dollars. “However the judge rules, whether for NIH or the plaintiffs, it ’ s likely to be appealed,” said Jennifer Hobin, Ph.D., director of science policy for the Federation of American Societies for Experimental Biology. “I wouldn ’ t be at all surprised if it winds up at the Supreme Court.” The Bethesda-based federation, the medical colleges ’ association, and the American Association for Cancer Research are all members of the Coalition for the Advancement of Medical Research. The coalition fi led an amicus brief with the court in support of all stem cell research — from adult stem cells and induced pluripotent stem cells to human embryonic stem cells. “At some point, science may overtake the need for [using] human embryonic stem cells, but we ’ re not there yet,” Mazzaschi said. “Our worry is that this issue has created such a toxic research atmosphere, it might affect the career choices of another generation of scientists.” Before sending the case back to Lamberth, the appeals court weighed in on the legal underpinnings of the case, with two of the three judges siding with the government. They called the language of Dickey – Wicker ambiguous and NIH ’ s interpretation of the law reasonable; the law bars federal funding “for the destructive act of deriving an ESC [embryonic stem cell] from an embryo” but not for a research project that might use these cells. In a dissenting opinion, however, a third judge, Karen LeCraft Henderson, accused her colleagues of “linguistic jujitsu.” Congress intended to stop federal funding of embryonic stem cells “in all of its sequences,” she wrote in her dissent.