[Genetic aspects of neoplasia]

The aggregation of cancer in families, possible causes of tissue specificity of hereditary susceptibility to cancer, as well as various kinds of inherited enzyme disorders regarded as the basis of this susceptibility are discussed. Different aspects of the relationship between cell neoplastic transformation and differentiation are analysed. Special attention is given to the capacity of differentiation inducers to reverse in some instances the malignant phenotype of the tumor cell progeny. In addition, some data are cited that indicate instability of DNA molecule in neoplastic cell transformation, differentiation and hormone action.