Advocates of cures with human embryonic stem cells are restless because President Obama has not delivered on his promise to lift restrictions on US federal government funding. All it takes, they moan, is a signature on a presidential executive order. But nothing is happening.

It may not be that simple, according to Nature. Although the reason for the delay may simply be that he is too busy managing the current economic crisis, there are also significant legal complications. According to Louis Guenin, of Harvard Medical School, the 1995 Dickey–Wicker amendment prohibits funding of research in which embryos are created or destroyed. Opponents of destructive embryo research are sure to pounce on any weakness in the legal instrument which loosens the purse-strings.

"I am concerned that an executive order is not sufficient to prevent what happened during the Bush administration on stem-cell research," John Gearhardt, an eminent stem cell scientist at the University of Pennsylvania, wrote to Harold Varmus, an important member of the Obama transition team.

In practice, the delay may make no difference because the recent advance in induced pluripotent stem cells seems to leave embryonic stem cells in the dust. "Stem cell research that requires destroying embryos is going the way of the Model T," says Richard M. Doerflinger of the US Conference of Catholic Bishops. "No administration that values science and medical progress over politics will want to divert funds now toward that increasingly obsolete and needlessly divisive approach." ~ Nature, Feb 24; Washington Post, Mar 2