Advances in knowledge and technology have revolutionized the process of drug development, making it possible to design drugs for a given target or disease. Building on the foundation laid by the previous three editions, Smith and Williams? Introduction to the Principles of Drug Design and Action, Fourth Edition includes the latest information on topics such as gene therapy, computeraided design, and molecular techniques including proteomics. Using real-world examples that illustrate the principles of drug design, the author explores the discovery of lead compounds and their manipulation in the production of non-toxic, metabolically stable drug candidates that will interact with target receptors in a predicted fashion.