For the new edition of this text on medicinal chemistry and molecular pharmacology, the authors have extensively updated the material to take into account advances since the publication of the second edition in 1998. They have added descriptions of new techniques of modeling, applications of genomics in drug design, therapies for Alzheimer's and other diseases, and emerging disorders like those of protein folding. Otherwise, the overall structure has remained unchanged with chapters first presenting the basic principles of medicinal chemistry and then looking at applications from a target- centered viewpoint.