In Reply: We agree with Dr Teitelbaum and colleagues that embryonic stem cells and induced pluripotent stem cells have extraordinary promise. However, in the review we and our coauthors were trying to point out that at the present time hematopoietic stem cells can be tested and used clinically, whereas the clinical use of embryonic stem cells still poses some technical challenges. We did not assert or intimate that the available evidence obviates the need to explore all sources of stem cells such as embryonic stem cells, neural stem cells, skin stem cells, or others. The review should simply be read as it was intended—a comprehensive overview of the clinical use of hematopoietic stem cells—and not as a commentary about the relative long-term value or merit of different types of stem cells.
Burt R, Kessler J, Loh Y. Hematopoietic vs Embryonic Sources for Stem Cell Research—Reply. JAMA. 2008;299(23):2746-2747. doi:10.1001/jama.299.23.2746-c