) Newly emerging technology for mutation detection and high-throughput sequencing of genes will make obsolete many of the previous and some of the current research strategies in the genetic epidemiology of cancer. The proposed UCI-UCSD Cancer Genetics Network (UCI-UCSD CGN) will be accomplished through the existing strengths of its co-investigators, community clinicians, existing resources, and previous experience in genetic epidemiology of cancer. Fundamental to the new NCI direction is the participation of clinicians, the community they serve, and basic scientists and epidemiologists. Also integral to the strategy is the dissemination of the growing body of genetic information to all participants and the provision of genetic counseling to those affected by the discovery of cancer mutations. The UCI-UCSD CGN will serve as an infrastructure for collaborative research investigations into the genetic basis of human cancer susceptibility. 1) The infrastructure will include basic network activities. These activities include the recruitment and follow-up of Network Participants, the collection and storage of core information, the maintenance of a local informatics system, a core laboratory for the processing and storage of biological specimens for specific projects, and the maintenance of informatics and communications technology to interface with the Nationwide Network. The UCI-- UCSD CGN will recruit potential enrollees from a total population of approximately 264,450 individuals. This population will include individuals at high-risk for cancer due to family history, members of the VA Desert Pacific Health Care Network, cancer patients including those with multiple primary cancer from the Cancer Surveillance Program of Orange, San Diego, and Imperial Counties, referrals from community clinics, physicians, and hospitals, and cancer survivors who are members of advocacy and community groups. Once enrolled, network members will complete a one-page interview of basic family history and risk factor information and will be followed annually. Genetic counseling and education will be made available to network members and referral physicians. 2) UCI-UCSD CGN will expand research capabilities to support Network activities, specifically in areas of molecular genetics, clinical genetics, genetic counseling, and education. A network of top quality principal investigators and co-investigators will provide an infrastructure for joint research efforts between scientists and clinicians. The UCI-UCSD CGN will sponsor scientific seminars and conferences that will facilitate the translation of molecular genetics research into clinical practice. The majority of the elements of the proposed network have already been established by our group and communications among them are in place.