The Radiation Injury Treatment Network® (RITN) provides comprehensive evaluation and treatment for victims of radiation exposure or other marrow toxic injuries. The goals of RITN are: 1. to develop treatment guidelines for managing hematologic toxicity among victims of radiation exposure, 2. to educate health care professionals about pertinent aspects of radiation exposure management, 3. to help coordinate the medical response to radiation events, and 4. to provide comprehensive evaluation and treatment for victims at participating centers.