Hodgkin's lymphoma (HL) is a malignant disease of the lymphatic system. In children, the 5 year event-free survival rate is approximately 90%. However, the currently used therapy is associated with severe late side effects. Reduction of treatment intensity might reduce the risk for late toxicities but might also increase the risk for relapses. Therefore, it is important to identify new targets for improvement of the current therapy and development of new treatment strategies.