Researchers will have access to a preassembled group of individuals who are informed about cancer genetics and have expressed an interest in participating in studies. The availability of potential study participants and the pooling of volunteers from the eight Network centers will make it possible to have sufficient numbers of people to answer important questions definitively.

Some of the scientific issues to be explored include:

• What is the prevalence of germline (heritable) mutations of familial cancer susceptibility genes in different populations?
• What determines whether someone with such an inherited genetic alteration gets cancer?
• What environmental exposures may interact with susceptibility genes to cause cancer?
• How can genetic discoveries be translated into cancer prevention strategies for susceptible individuals, and into more effective treatments?
• What ethical, psychological, social, and family issues affect healthy individuals and their families who carry cancer susceptibility gene mutations?