Genes are important modifiers of the human response to drugs, hormones, and toxins. Medical patients and healthy individuals alike display significant differences in response and suffer adverse effects as a result of exposure to many therapeutic agents and occupational chemicals. In thissubstantially revised second edition, highly regarded authority Wendell Weber brings together laboratory methods and epidemiologic studies in defining the role of heredity in human drug response. The book is divided into two major sections, one covering pharmacognetic concepts and the second theapplication of those concepts. The first edition was published in 1997, and a vast amount of new information about the genetics of human drug response has accumulated since then. In just five years, we have moved from mapping the first complete sequence of a free-living organism to a working draft of the human genome. Theapplication of tools for analyzing genetic variation and the maturation of the human genome initiative has provided a wealth of primary genetic information and functional genomic data to fuel our understanding of genetic variation. Today, pharmacogenetics comprises a well-integrated network ofphysicians and scientists worldwide who are attempting to identify variations in human disease and drug response and how they might use this information to discover new, more effective drugs and avoid unwanted drug responses.