Personal and family medical history must be verified through questionnaires, interviews, and review of pathology slides and medical records. For known or suspected familial syndromes in which no gene has been identified, two or more living affected cases among family members are required for participation. The types of familial syndromes under active accrual and study are predominantly investigator-and hypothesis-driven. This approach permits CGB investigators to remain alert to the opportunities afforded by unexpected clusters of rare tumors in families and individuals, and to tailor the accrual of families with specific types of syndromes to meet programmatic goals. This requires that CGB investigators remain abreast of both general knowledge and state-of the-art developments in clinical oncology, genetics, epidemiology and molecular biology, so that critical research opportunities can be recognized when they present, and so that thoughtful decisions can be made regarding the commitment of the resources needed to conduct such studies.