The year 2003 marks the tenth anniversary of the first use of the acronym Stat (also written STAT ) in the scientific literature for a family of transcription factors which rapidly transducer cytokine a- and growth factor-elicited signals from the plasma membrane to the cell nucleus thereby activating gene transcription (thus, Signal Transducers and Activators of Transcription). The only fully comprehensive reference for what is known about STAT proteins and their biology, this book describes the current state of ongoing research in this broad area, and looks toward the future to try to predict the discoveries that lie ahead. With contributions from the very best experts in the field, it will prove useful to both the novice and the expert, providing a didactic overview of the STAT transcription factor field, a summary of past literature, current developments , and new uncharted, perhaps controversial, ideas and questions about STAT activation and biology.