Discoveries that a small subset of cellular genes --- proto-oncogenes --- are frequent targets of carinogenic insults or chance that convert them to oncogenes have opened new areas of approach to understanding and eventually controlling the events leading to cancer. New technology has made it possible not only to identify genes involved in the etiology of cancer, but to dissect their molecular composition.

This symposium brought together scientists from areas of carcinogenesis and molecular biology to review the state-of-the-art in this field. The papers presented in this proceedings volume can be grouped into four broad areas: the mechanisms of onc gene activation and associations of onc genes with tumours, the mechanisms of onc gene action, the physiology of proto-onc genes, and the discovery and characterization of new onc genes.