The Radiation Effects Research Foundation is the scientific research institution focused on the study of health effects of radiation in the survivors of the atomic bombings of Hiroshima and Nagasaki. Careful analysis of the accurately recorded cancer incidence and mortality data for the large study population is contributing fundamental risk information for radiation protection standards worldwide. Routine clinical examinations provide further health observations and contribute to the well-being of the participants. RERF is a binational organization supported by the governments of Japan and the United States, but it welcomes scientists from all countries to participate in its epidemiological and radiobiological studies. RERF's research is conducted for peaceful purposes to understand the health effects of radiation for the benefit of all people.