) The 1997 Gordon Research Conference on Molecular Concepts in Radiation Oncology will be held at Plymouth State College, June 29 to July 4, 1997. The conference will bring together approximately 130 active investigators in the molecular aspects of the radiation response of cells and tissues relevant to radiation oncology. This proposal requests funds to provide partial support for travel and subsistence, expenses for invited participants from North America and overseas. Recent years have seen an explosion of our understanding of the effects of ionizing radiation and the cell. Several genes involved in determining the sensitivity of cells to ionizing radiation (IR) have been identified and cloned. Pathways of signal transduction and cell cycle checkpoints following IR have been identified, and the relationship between various genes, cell cycle checkpoints following IR have been identified, and the relationship between various genes, cell cycle arrest and apoptosis is beginning to be understood. These new developments offer an unprecedented new opportunity for cancer treatment by radiation therapy, including its use in gene therapy. This conference will bring together the experts in these fields to discuss these new developments and to explore their potential for advances in cancer treatment by radiation oncology.