Cell Signaling provides undergraduate and graduate students with the conceptual tools needed to make sense of the dizzying array of pathways that cells use to detect, process, and respond to signals from the environment. By emphasizing the common design principles and molecular processes that underlie all signaling mechanisms, the book develops a broad conceptual framework through which students can understand diverse signaling pathways and networks. The book first examines the common currencies of cellular information processing and the core components of the signaling machinery. It then shows how these individual components link together into networks and pathways to perform more sophisticated tasks. Many specific examples are provided throughout to illustrate common principles, and to provide a comprehensive overview of major signaling pathways. Thoroughly revised, this second edition includes two new chapters and substantial updates to the text and figures throughout the book. Key features: The book provides a conceptual framework through which all signaling pathways can be understood without memorization of details It is extensively illustrated, including high-quality diagrams and schematics to elucidate important concepts and processes Each chapter concludes with a useful summary section that brings together the key concepts End-of-chapter review questions test the reader's understanding of the material covered Two new chapters have been written especially for this edition: "Signaling and Disease" and "Diversity in Signaling across Phylogeny"