Abstract
Certain genetic disorders in man may serve as models for the study of carcinogenesis, which may, in turn, lead to new means of prevention and treatment. In some disorders, there is an increased probability that normal cells will be transformed into cancer cells. In others, cancer seems to result from defective host resistance to transformed cells. In still other genetic disorders, the role of chromosomal abnormality and of viral infection in the origin of cancer can be investigated.