Growth factors are elaborated to control the growth of cells in such physiological processes as wound healing, tissue regeneration and the immune response. Abnormal production of these growth factors, their receptors or intracellular med!ators of their action may lead to disease states including oncogenesis. This volume will focus on exciting developments in defining the precise molecular lesions that permit the conversion of controlled proliferative signals to neoplasia, on the possible involvement of growth factors in the development of blood vessel diseases as seen in diabetes and atherosclerosis, on the altered immune surveillance that leads to autoimmunity and on the fundamental mechanisms by which growth factors signal their target cells. We expect that the contents of this volume will help promote understanding of the role of these fundamental biological processes and their alterations in a wide variety of disease states and stimulate new investi gations in this important area of biomedical research. The Editors v CONTENTS PERSPECTIVES ON THE CONTROL OF GROWTH AND DIFFERENTIATION Perspectives on the Biology of Growth Factors . . . . . . . . . . . . . . . . . . I. B. Fritz Platelet-Derived Growth Factor- Its Role in Health and Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 R. Ross and E. W. Raines Molecular and Developmental Biology Aspects of Fibroblast Growth Factor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 D. Gospodarowicz Chemical and Biochemical Properties of Human Angiogenin. . . . . . . . . . 41 B. L. Vallee and J. F. Riordan GROWTH FACTOR - ONCOGENE RELATIONSHIPS Structure - Function Relationships in Cellular andViral fps/fes Cytoplasmic Protein-Tyrosine Kinases. . . . . . . . . . . . . . . . . . . . . . . . 55 T. Pawson. P. Greer, M. Moran, K.