ment (NIH, 2001), the 2007 Guidelines deemed those lines to have been acceptably derived (see Sections 1.4 and 1.5 and associated discussion in NRC and IOM, 2007). In light of questions raised when the present report was already near completion about the derivation or use of some of those lines (Streiffer, 2008), and as per its charge, the Committee will monitor developments as to the ethics and policy regarding the lines in question in order to consider whether any future changes in the Guidelines are warranted. Stem cell research oversight committees are, of course, free to set their own policies about the use of these lines according to the principles outlined in Section 1.6 of the Guidelines (as renumbered in this document). The Committee is also aware that the scientific and oversight communities desire additional guidance on how to evaluate research that requires the development of chimeras. In response, the Committee has added some text in the new Section 7.3(c) [as well as 1.3(b)] and also plans to address research involving chimeras at the meeting it is organizing for November 2008.

These amended Guidelines supersede those issued in 2005 and 2007 by the Committee on Guidelines for Human Embryonic Stem Cell Research and the Human Embryonic Stem Cell Research Advisory Committee, respectively. It is important that the clarifications and amendments presented here be interpreted in the context of the complete set of amended Guidelines, which is included at the end of this report (Appendix A). In addition, the glossary included in the 2005 Guidelines for Human Embryonic Stem Cell Research (NRC and IOM, 2005) has been amended by adding definitions for the terms hPS cells and multipotent, and the entire glossary is reprinted as Appendix B.

The original Guidelines released in 2005 were addressed specifically to research with hES cell lines, although institutions and investigators conducting research on human adult stem cells or fetal stem cells were encouraged to “consider which individual provisions of these guidelines are relevant to their research.” Because the Guidelines were developed primarily for research with hES cells, however, it was not made explicit which provisions of the Guidelines might apply to other types of stem cells.

There have been several recent reports on reprogramming of somatic cells to pluripotency (for definitions see glossary, Appendix B). In light of the production of so-called induced pluripotent stem (iPS) cell lines derived