In 1978 the Dutch Genetic SOciety organized a symposium on the genetic aspects of the origin of tumor cells. The objective of this symposium was to reach an overview of the state of knowledge in a number of quite different fields related to each other through the genetics of the initiation of tumor cells. This monograph contains the brought-up-to-date contributions of this symposium. Herein discussed is the extent that characteristics of tumor cells can be considered as a phenotype. The possible role of somatic mutation and repair of genetic damage is studied and the analysis of genes with...