This two-part series, a response to the recent appeals court decision lifting an injunction on federal funding of human embryonic stem cell research, was co-authored by M. William Lensch, George Q. Daley, and Leonard Zon of the Stem Cell Research Program at Children’s Hospital Boston. (Read Part 1.)

While there is reason for optimism, the April 29 appeals court ruling lifting the injunction on federal funding for human embryonic stem cell (hESC) research will not be the last chapter in the story of such research in the United States. And there are moments in this story that hold cause for greater alarm. …

This two-part series, a response to the recent appeals court decision lifting an injunction on federal funding of human embryonic stem cell research, was co-authored by M. William Lensch, George Q. Daley, and Leonard Zon of the Stem Cell Research Program at Children’s Hospital Boston.

It came as a welcome relief when on April 29 the U.S. Court of Appeals vacated a lower court’s injunction against federal funding of human embryonic stem cell (hESC) research. For those of us working on research projects involving hESCs, whether funded through the National Institutes of Health (NIH) or other federal agencies, it meant that we are once again free to continue our work … for now.

The “for now” part relates to the fact that the recent ruling is but one chapter in the ongoing story of hESC research funding. The desultory nature of federal funding for hESC research has been a constant source of uncertainty for scientists and the general public alike, and to understand the full story, we need to look back to the mid 1990s, before the derivation of the first hESC lines. …