|GENEPI 2 aims at the qualitative and quantitative further development of the European tissue bank and database GENEPI-ENTB, established with EURATOM support in FP5. It is dedicated to research in radiation effects and in the genetic determinants of the variation in individual radio-sensitivity. With tissues from more than 4.200 patients linked to solid outcome data stored, GENEPI is currently the largest infrastructure in this field worldwide.The final aim is to more than triple that number to enable the selection of statistically relevant groups for analysis and to keep all future avenues of research open. An inestimable plus value for the GENEPI tissues (DNA or lymphocytes and other normal and tumour tissues) obtained from radiotherapy patients is the database linked to it. For each tissue, treatment data (dose distributions with dose gradients, total dose, dose per fraction) and outcome data are recorded.It will be a major objective for GENEPI 2 to develop the tools to make these rich data easily searchable and available for distant querying. Another powerful new feature to be developed in GENEPI 2 aims at creating a logistical shortcut for the quest to identify the hypersensitive phenotype. Tissues will be collected from a group of patients who demonstrated an unexpectedly severe response to RT (+/- 1 out of 1000). This action will necessitate the collaboration of a large segment of the European RT community. Major attention will be paid to all aspects of quality assurance. A steering committee will oversee all protocols, use and access.Finally, a close collaboration will be established with the "GENEPI-Low RT" consortium intent on using the GENEPI resource for its proposed "Low dose radiosensitivity" project submitted for this call as well as with other candidate users a.o. a working party preparing a joint study on radiation response to high doses. ESTRO will be the custodian of ethical issues and handle dissemination, training and project management.