This is a revised application for the postdoctoral Mayo Cancer Genetic Epidemiology Training Program (MCGETP). Revisions include addition of a senior laboratory Co- Director, an External Advisory Committee, improved selection/retention processes to ensure a full three year training experience, and documented commitment of the institution. The goal of the MCGETP is to produce investigators capable of developing an independent academic career in the evolving arena of cancer research that transects the disciplines of genetics, epidemiology, bioinformatics, and biostatistics. This interdisciplinary training will prepare them to meet the challenges of bridging the laboratory-translational interface, and to stimulate improvements in cancer detection, prevention, and treatment. Mayo Clinic is a highly respected center for medical training, research, and patient care, and has proven to be an outstanding environment for nurturing such integrated training. The resources of the Mayo Clinic Comprehensive Cancer Center are available to this program. We seek continuing support for the MCGETP to provide three-year interdisciplinary training experiences for three types of trainees (doctoral level individuals prepared in a) laboratory-based research, b) medicine, or c) epidemiology or biostatistics). With oversight by two Advisory Committees composed of senior faculty and external advisors, the MCGETP will ensure an integrated didactic education through a specialized core curriculum tailored to the MCGETP, opportunities through additional intramural and extramural courses and workshops in cancer biology, genetic epidemiology and analysis, and an individualized mentoring program that includes study design and development of original data and/or analyses for a research grant application. The co-mentoring structure for each trainee ensures that they receive the benefit of multiple research perspectives and opportunities. The base of 37 faculty/mentors include nationally and internationally known investigators in their respective fields, who have a track record of consistent funding, and demonstrated excellence in mentoring junior investigators. Each trainee is also integrated into highly interactive multidisciplinary tumor working groups at Mayo to enhance their research experience. Evaluation of trainees is performed on a regular basis, and they are expected to generate a research grant proposal that would be suitable for submission for competitive funding. Thus, through the MCGETP, trainees will be prepared to combine laboratory-based genetics research with clinical and population sciences studies. In turn, this will address a major need for cancer investigators with genetic and molecular epidemiology expertise who can best exploit rapidly developing genetics, bioinformatics, and analytic technology for improving our approaches to cancer prevention and care.