How is growth controlled in normal cells? How are the growth control mechanisms perturbed in cancer cells? This book provides an up-to-date description of research aimed at resolving these questions. It is organized into four sections, each containing a series of short reviews written by experts in the field. The general headings are: growth factors, receptors, and related oncogenes: transduction of mitogenic signals and ras oncogenes; nuclear oncogenes and regulation of gene expression; and multiple steps involved in malignant transformation. The articles emphasize concepts rather than detailed facts and are intended not only for specialists in the field but also for interested readers, such as physicians and advanced students, who wish to stay abreast of developments in one of the most exciting fields in current biomedical research.