original extended abstracts by the presenters are included as Attachments 1 through 4. In addition, the presenters’ slides and the audio from the meeting are available on the Emerging Issues Committee’s Web site.⁴

Kenneth S. Ramos, of the University of Louisville and co-chair of the workshop planning committee, opened the workshop with welcoming remarks, background on the standing and workshop planning committees, and speaker introductions. Ramos also provided a brief historical perspective on the technological advances and applications of toxicogenomics. Beginning in the early 1980s, new technologies, such as those based on polymerase chain reaction (PCR),⁵ began to permit evaluation of the expression of individual genes. Recent technological advances (for instance, the development of microarray technologies) have expanded those evaluations to permit the simultaneous detection of the expression of tens of thousands of genes and to support holistic evaluations of the entire genome. The application of these technologies has enabled researchers to unravel complexities of cell biology and, in conjunction with toxicologic evaluations, the technologies are used to probe and gain insight into questions of toxicologic relevance. As a result, the use of the technologies has become increasingly important for scientists in academia, as well as for the regulatory and drug development process.

John Quackenbush, of the Dana-Farber Cancer Institute and co-chair of the workshop, followed up with a discussion of the workshop concept and goals. The workshop concept was generated in response to the standing committee’s and other groups’ recognition that the promises of toxicogenomic technologies can only be realized if these technologies are validated. The application of toxicogenomic technologies, such as DNA microarray, to the study of drug and chemical toxicity has improved the ability to understand the biologic spectrum and totality of the toxic response and to elucidate potential modes of toxic action. Although early studies energized the field, some scientists continue to question