E. GRUNDMANN On behalf of the "Gesellschaft zur Bekampfung der Krebskrankheiten Nordrhein- Westfalen e. V. " I welcome you in Dusseldorf. During these two days problems of oncogenesis have to be discussed. The participants have been selected with the inten- tion of giving a review of the various fields which have some bearing on this topic. So you see here biochemists, cytologists, pathologists, immunologists, pharmacologists, virologists, and so on. Only by extensive cooperation of all scientists concerned in this field can this difficult problem of carcinogenesis ever be cleared up. Once the causal relations have been identified, we may have a reliable basis for cancer treat- ment. Research on oncogenesis is of great interest, but it is only a part of the worldwide cancer campaign. It is our hope that this symposium will contribute towards helping the cancer patient. He is the center of all our efforts. Keeping this in mind - let us begin! General Problems of Carcinogenesis Molecular Mechanisms in Chemical Carcinogenesis P. N.MAGEE Covalent binding of metabolites of the hepatocarcinogenic azo dye p-dimethyl- aminoazobenzene (DAB) to proteins of the livers of rats to which it had been ad- ministered was observed by JAMES and ELIZABETH MILLER in 1947. Since then a large amount of work on the interaction of many other chemical carcinogens with cellular macromolecules has been reported.
