As in the Stem Cells volume in this series, a writer specializing in health and environmental topics seeks to clear up public misconceptions of another promising but controversial advance in medicine. Kelly offers an accessible introduction to the history and continuing development of gene therapy (which really is many therapies), its applications, the regulatory debate in the US, status elsewhere, and ethical/religious concerns. Appendices include a substantial annotated list of primary sources, timeline of milestones in the field, further reading, and a glossary of terms. Annotation ©2007 Book News, Inc., Portland, OR (booknews.com)