[The role of epidemiology and experiments in the study of carcinogenesis].

Mutual understanding and collaboration of epidemiologists and experimental scientists are very important for the study of chemical carcinogenesis. This article reviews limitation and prospect of epidemiological and experimental studies: Limitation of epidemiology and roles of experimental studies. Limitation of experimental studies and roles of epidemiology. Collaborations of epidemiologists and experimental scientists. Expectation to epidemiologists in Japan.