As more and more problems with the use of embryonic stem cells come to light, adult stem cells are beginning to emerge as the leading therapeutic hope, writes a British researcher in The Lancet. Neil Scolding, of the University of Bristol, says that embryonic stem cells are not currently being used to develop therapies, but rather to improve research techniques. Therapeutic cloning would probably require too many human eggs and would be hazardous, as well.

Dr Scolding says that the case for adult stem cell therapies took a pounding in 2002. After it was shown that some adult stem cells fuse, some scientists concluded that they could not be multipotent. However, further research has shown that “fortunately, for the now highly expectant patient, reports of the death of adult stem cells were greatly exaggerated”. Fusion may actually have a role to play in tissue repair. Furthermore, 50 years of clinical bone marrow transplantation have made it possible to make rapid progress towards therapies for heart attacks, chronic heart failure, stroke and other diseases with adult stem cells. “The next few years, not decades, will show whether adult stem-cell treatments are to join the mainstream therapeutic arsenal,” Scolding concludes.