Transforming growth factor-b (TGF-b), identified nearly three decades ago, is a secreted polypeptide that functions in critical cell cycle processes, including cellular proliferation, differentiation, and development. It belongs to a large protein family that, in humans, contains 33 members, including activins, inhibins, bone morphogenetic proteins, growth and differentiation factors, and Müllerian inhibiting substance. This volume draws on the world's leading laboratories to comprehensively cover all aspects of the biology of TGF-b and related factors. In addition to providing historical and background information, it describes the cell biology and signaling pathways of TGF-b members in detail, including the roles of TGF-b factors in the development and physiology of humans and model organisms. The last few chapters are devoted to the role of TGF-b members in cancer and other diseases, as well as the possibilities for therapeutics based on knowledge of signaling pathways and macromolecular structures. It serves as a comprehensive reference work for both specialists and researchers less familiar with the field.