This volume will provide researchers with recent information on bioactivation reactions of drugs and toxicants and will provide examples of how molecular and genomic biology, proteomics, mass spectrometry, and computational modeling are used in bioactivaton research. In other sections of this volume, focus will be on recent applications of bioactivation research in pharmacology, toxicology, and environmental health sciences. In these sections, the contributors will demonstrate the integration of bioactivaion research in several research areas, including new drug design, drug development, mechanisms of cell death, toxicity and carcinogenicity, metabolite-specific biomarkers of exposure and effect, and extrapolations of results from animal models to humans.