This classic immunology text for undergraduates keeps pace with the constant evolution in our understanding of the immune system while maintaining a clear focus on the concepts of immunology. The text provides a straightforward overview of the subject and is accessible to students with diverse preparation, from biology to allied health majors. Coverage of new discoveries in the field makes this the most current text available. Features: * Major experimental procedures are highlighted in boxes to stress that immunology is an experimental science. "A Closer Look" boxes provide a more in-depth examination of various aspects of specific topics. * Multiple choice questions and open-ended problems and exercises test students' memory retention and critical thinking skills. * An extensive glossary defines all terms: key terms are also marked within the text. A detailed illustration program helps clarify concepts. * Comparative approach to the subject draws examples from outside the usual human or mouse area. New to this edition: * The text features new coverage on many topics including: nitric oxide, chemokines, apoptosis, new cytokines, the BCR complex, antigen procssing, new information on AIDS, use of DNA for vaccination. * Three new review chapters (2, 3, and 7) on microbiology, biochemistry, and cell biology respectively give students a quick refernce for this material as it relates to immunology. * New chapter openers profile eminent immunologists and provide historical perspective.