It was just 18 months ago that U.S. scientists studying embryonic stem cells thought their nearly decade-long battle for federal funding was finally won. President Obama had signed an executive order ending a restrictive policy enacted in 2001 by President Bush. That policy had blocked federal funds from being used to study most human embryonic stem cells. But a surprise ruling by a lower court last week left the stem-cell community stunned. A federal judge issued an injunction, blocking federal funding for any research involving embryonic stem cells.