Nongenotoxic Carcinogenesis

"What is a nongenotoxic carcinogen?" This question recurred through­ out the Ernst Schering Research Foundation Workshop on nongeno­ toxic carcinogenesis, underlining the complexity of the topic. The clarity of the view that all carcinogens act by mutating DNA, origin­ ally advocated by Bruce Ames nearly 20 years ago, has been clouded by the increasing numbers of compounds which are not genotoxic but which nevertheless can cause cancer. There is an urgent need to in­ crease our understanding of