Abstract
During recent years the viewpoint has become prevalent that neoplasia is a type of tissue reaction which can be provoked by various types of appropriate stimuli, e.g., hormonal, other chemical, physical, and viral. This report deals with the comparative biology of cellular responses to subdamaging, injurious (irritating) agents, in general, and presents the viewpoint that dependent neoplasia may represent a special case of the well-known phenomenon of reaction-to-injury. Current theories of cancer are discussed in relation to autonomous neoplasia.