th The 13 Jerusalem Symposium on Quantum Chemistry and Bio- chemistry was dedicated to the memory of Ernst David Bergmann, one of the founders of this series of Symposia, at the occasion of the 5th anniversary of his death. The opening session was honored by the pre- sence of H. E. Yzhak Navon, President of the State of Israel and of Baron Edmond de Rothschild whose generous and constant support makes these Symposia possible. To both these distinguished guests we address the expression of our deep gratitude. Our thanks are also due to the Israel Academy of Sciences and Humanities, in particular to its President Professor Aryeh Dvoretzky and to the Hebrew University of Jerusalem for their hospita- lity and helpful association. I had the privilege this time to join efforts in the organi- zation of this Symposium with two distinguished American colleagues, Prof. P. O. P. Ts'o from Johns Hopkins University and Dr. Harry Gelboin from the National Institute for Cancer Research. I wish to thank them for their invaluable help and the two Institutions which they repre- sent for important financial support. th The subject of the 13 Jerusalem Symposium brings us back to that of the 1st Symposium held in 1967. The comparison of the two Proceedings enables us to evaluate the important developments which occurred in this field of research during the last 13 years.

In 1980. a distinguished group of scientists gathered In Washington. D. C. for an International Symposium on Aging and Cancer. Among the recommendations of this Symposium was to convene a future meeting to discuss the molecular basis for Interrelationships between aging and cancer when the appropriate scientific knowledge was available. That same year. the 13th Jerusalem Symposium on Quantum Chemistry and Biochemistry entitled .Carcl nogenesls: Fundamental Mechanisms and Environmental Effects.. was held. attended by some 50 International authorities In this field. At this meeting. It became clear that the fundamental process of carcinogenesis 15 Intimately associated with differentiation. which must also be mechanistically related to aging. It was therefore proposed that the next Jerusalem Symposium on Cancer could provide the appropriate forum for the study on the Interrelationship among cancer. aging and differentiation. The Impressive advances In our knowledge of the nature of the genome through molecular genetic and physical chemical techniques have now provided the opportunity to examine the Interrelationships between these complex biolo gical processes. Through the Isolation. cloning and rearranging of genes we are able to dissect and manipulate the genome In a fashion that was unanticipated only a decade ago. At the same time. the Increase In longevity and the Increased numbers of Individuals entering the last decades of life where cancer Incidences are highest raise the profound and practical question of whether aging and cancer are linked through common mechanisms."

In 1980. a distinguished group of scientists gathered In Washington. D. C. for an International Symposium on Aging and Cancer. Among the recommendations of this Symposium was to convene a future meeting to discuss the molecular basis for Interrelationships between aging and cancer when the appropriate scientific knowledge was available. That same year. the 13th Jerusalem Symposium on Quantum Chemistry and Biochemistry entitled .Carcl nogenesls: Fundamental Mechanisms and Environmental Effects.. was held. attended by some 50 International authorities In this field. At this meeting. It became clear that the fundamental process of carcinogenesis 15 Intimately associated with differentiation. which must also be mechanistically related to aging. It was therefore proposed that the next Jerusalem Symposium on Cancer could provide the appropriate forum for the study on the Interrelationship among cancer. aging and differentiation. The Impressive advances In our knowledge of the nature of the genome through molecular genetic and physical chemical techniques have now provided the opportunity to examine the Interrelationships between these complex biolo gical processes. Through the Isolation. cloning and rearranging of genes we are able to dissect and manipulate the genome In a fashion that was unanticipated only a decade ago. At the same time. the Increase In longevity and the Increased numbers of Individuals entering the last decades of life where cancer Incidences are highest raise the profound and practical question of whether aging and cancer are linked through common mechanisms."

th The 13 Jerusalem Symposium on Quantum Chemistry and Bio- chemistry was dedicated to the memory of Ernst David Bergmann, one of the founders of this series of Symposia, at the occasion of the 5th anniversary of his death. The opening session was honored by the pre- sence of H. E. Yzhak Navon, President of the State of Israel and of Baron Edmond de Rothschild whose generous and constant support makes these Symposia possible. To both these distinguished guests we address the expression of our deep gratitude. Our thanks are also due to the Israel Academy of Sciences and Humanities, in particular to its President Professor Aryeh Dvoretzky and to the Hebrew University of Jerusalem for their hospita- lity and helpful association. I had the privilege this time to join efforts in the organi- zation of this Symposium with two distinguished American colleagues, Prof. P. O. P. Ts'o from Johns Hopkins University and Dr. Harry Gelboin from the National Institute for Cancer Research. I wish to thank them for their invaluable help and the two Institutions which they repre- sent for important financial support. th The subject of the 13 Jerusalem Symposium brings us back to that of the 1st Symposium held in 1967. The comparison of the two Proceedings enables us to evaluate the important developments which occurred in this field of research during the last 13 years.