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.