Miami Winter Symposia, Volume 18: Cellular Responses to Molecular Modulators is a collection of papers presented at the 13th Miami Winter Symposium held in Miami Beach in 1981 through the joint effort of the University of Miami School of Medicine and the Papanicolaou Cancer Research Institute. Separating 27 manuscripts into chapters, this book begins with a discussion on protein structure and function. This topic is followed by considerable chapters devoted to a whole series of molecules that precisely and specifically modulate a particular behavior and that can be studied in detail in isolated cells in culture. These chapters also look into the research studies on mitogen receptor cytobiochemistry, including special insertion properties and internal migratory fate after binding to effectors. Other chapters discuss the primary gene product containing the thymosin a1 sequence; the purification and production of interferons from cell cultures; the biochemical mechanisms by which interferons modulate cell behavior; and the ability of interferons to regulate natural killer lytic activity at the single cell or population level. The concluding chapters explore the distinct interferon classes by their antigenic, biological, and chemical properties. This book will be of great benefit to cell biologists and researchers.