In 2001, former President George W. Bush cast a cloud over this field of science by barring the National Institutes of Health (NIH) from funding research that used embryonic stem cells beyond the 60 cell lines that already existed. But in 2009, then-President Barack Obama signed an executive order repealing Bush’s policy. Obama’s decision enabled researchers like Goldstein, director of the UC San Diego Stem Cell Program, and Sanford Stem Cell Clinical Center, to make real progress, inching closer to human clinical trials. The Clinton administration on Wednesday will unveil long-awaited guidelines that will allow U.S. scientists for the first time to conduct research on human embryo cells