When White House political adviser Karl Rove signaled last week that President Bush planned to veto the stem cell bill being considered by the Senate, the reasons he gave went beyond the president’s moral qualms with research on human embryos.

In fact, Rove waded into deeply contentious scientific territory, telling the Denver Post’s editorial board that researchers have found “far more promise from adult stem cells than from embryonic stem cells.”

But Rove’s negative appraisal of embryonic stem cell research – echoed by many opponents of funding for embryonic stem cells – is inaccurate, according to most stem cell scientists.

“(Rove’s) statement is just not true,” said Dr. Michael Clarke, associate director of the stem cell institute at Stanford University, who in 2003 published the first study showing how adult stem cells replenish themselves.

If opponents of embryonic research object on moral grounds, “I’m willing to live with that,” Clarke said, though he disagrees. But, he said, “I’m not willing to live with statements that are misleading.”

Last week, the journal Science published a letter from three researchers criticizing the claim that adult stem cells are preferable to embryonic stem cells. The authors included Dr. Steven Teitelbaum of Washington University in St. Louis, who has used adult stem cells to treat bone diseases in children.

The authors wrote that the exaggerated claims for adult stem cells “mislead laypeople and cruelly deceive patients.”

White House spokesman Ken Lisaius on Tuesday could not provide the name of a stem cell researcher who shares Rove’s views on the superior promise of adult stem cells.