The company, called StemCells, is betting that its proprietary preparation of stem cells from fetal brain tissue will take on many different roles in the central nervous system. The company and its collaborators have already shown that its stem-cell product has potential in protecting vision in diseased eyes, acting as brain support cells, or improving walking ability in rodents with spinal cord injury.

This metamorphic ability is not so surprising—they are stem cells, after all. But experts say the quality of scientists involved in StemCells and the interesting properties of its cells sets the company apart. "They've really been steadfast in their work to get these cells into clinical trials. That is a tough road and they've done it," says Larry Goldstein, a neuronal stem-cell researcher and director of UC San Diego's stem-cell program.

The company discovered the technique to isolate these cells from brain tissue in 1999 and has since spent some $200 million improving the technology. "Now we are really in the exciting phase, because now we are looking at human clinical data, as opposed to just small animals," says StemCells CEO Martin McGlynn.

His company is not the only group bringing stem cells into the clinic. While much attention was paid to Geron's departure from the world's first embryonic stem cell trial (see "Geron Shuts Down Pioneering Stem-Cell Program"), many other groups have continued to push their non-embryonic stem-cell therapies forward for leukemia, colitis, stroke, and more. Meanwhile, Advanced Cell Technology continues its U.K.-based embryonic stem-cell therapy trials for blindness. Non-embryonic stem cells can come from a variety of sources—bone marrow, blood, as well as donated aborted fetal tissue, as is the case with StemCells and Neuralstem, another company focused on neuronal stem cells. In recent years, scientists have also developed methods for turning normal adult cells into stem cells (so-called induced pluripotent stem cells), but their safety has yet to be tested in humans.