The Breast and Ovarian CFRs facilitate and support interdisciplinary and population-based research on the identification and characterization of breast and ovarian cancer susceptibility genes, with particular emphasis on gene-gene and gene-environment interaction research. Available from the registries are: a) family history, epidemiologic and clinical data, b) updates on cancer recurrence, morbidity and mortality in participating families, and c) biospecimens, including plasma, lymphocytes, serum, DNA, Guthrie cards or buccal smears, and paraffin blocks of tumor tissue