Abstract
Stem cell science, using both embryonic and a variety of tissue-specific stem cells, is advancing rapidly and offers promise to improve medical care in the future. Yet, with the notable exception of hematopoietic stem cell transplantation, a long-established approach to treating certain cancers of the blood system, this promise is long term and most stem cell research focuses on basic scientific questions or the collection of pre-clinical data. Although some clinical trials are underway, most are focused on safety, and novel effective therapy is likely a long way off. Despite the preliminary nature of most stem cell research, however, numerous clinics around the world offer stem cell “therapies” to patients today outside the context of a clinical trial. Although the number of patients who have received these stem cell-based interventions is unknown, anecdotal reports suggest a substantial population of patients is willing to try them, despite unresolved questions about their safety and efficacy.