The Immune System, Fourth Edition emphasizes the human immune system and presents immunological concepts in a coherent, concise, and contemporary account of how the immune system works. Written for undergraduate, medical, veterinary, dental, and pharmacy students, it makes generous use of medical examples to illustrate points. This classroom-proven textbook offers clear writing, full-color illustrations, and section and chapter summaries that make the book accessible and easily understandable to students. The Fourth Edition is a major revision that brings the content up-to-date and improves clarity. Based on user feedback, there is now increased continuity and connectivity between chapters. The Immune System is additionally supported by the Garland Science Learning System. This homework platform is designed to evaluate and improve student performance and allows instructors to select assignments on specific topics and review the performance of the entire class, as well as individual students, via the instructor dashboard. Students receive immediate feedback on their mastery of the topics, and will be better prepared for lectures and classroom discussions.