A new chapter in the medical detective story about neoplastic disease following irradiation in childhood is presented by Doctors Saenger, Silverman, Sterling, and Turner in this issue of Radiology. It is an important contribution to our knowledge of radiation effects, made through skillful use of the research methods of epidemiology. Some of the findings might have been predicted from previous work: the greatly increased incidence of thyroid cancer in the irradiated children, for example. On the other hand, the increased leukemia incidence which some investigators have observed after irradiation was not found. The irradiated children had a distinctly higher percentage of disabling diseases in general than their siblings but, most surprisingly, a substantially lower total mortality than either siblings or the general population. This is a highly provocative study, and the thoughtful, scholarly, and sophisticated discussion given by the authors is as valuable as are the data they present. The problems remai...