[Model systems for investigation of genetic factors in tumorigenesis]

The steadily rising public concern about the number and amounts of carcinogenic agents in our environment has led to a decline in interest in another aspect of tumorigenesis, namely the involvement of genetic factors in the processes that lead to malignant tumors. It is becoming evident that both the noxious influences in the environment and the genetic make-up of cells or the whole individual are involved in cancerous processes to a similar extent. The usefulness of experimental animal models for analysis of the extreme complexity of the molecular mechanisms underlying tumor formation is demonstrated by recent results in experimental oncology.