Provides detailed information about the signal transduction pathways used by interferons to activate gene transcription. In addition, this book discusses how the same pathways are used by many other cytokines and thus provide a forum for cross-talk among these important biological response modifiers. Additionally, the book introduces the interferon system and describes the interferon-inducible genes whose products are responsible for the cellular actions of interferons. The nature of the interferon receptors and how the transcriptional signals are transmitted from the receptors on the cell surface to the genes in the nucleus are discussed in detail. Finally, the use of similar pathways of signal transduction by other cytokines is highlighted.