Two years ago, Evan Snyder, a developmental and child neurologist, was working at the Harvard Medical School, transplanting neural stem cells into the damaged brains and spinal cords of mice and other animals and watching them reconstitute tissue or recover function. “I had just moved to better lab space,” Snyder recalled in June at the Argent Hotel in downtown San Francisco, where he'd gone to attend the Biotechnology Industry Organization's annual conference (BIO 2004). At the time, President Bush had recently announced strict limits on federal funding for embryonic-stem-cell research, and Snyder, like many scientists, sensed the federal government's troubled and hesitant relationship with a field he considered deeply promising.