The purpose of this proposal is to provide continuing support for an organized program of interdisciplinary training for 24 postdoctoral fellows in defined areas of basic research that are likely to lead to insights into fundamental mechanisms of cancer. The basic research, conducted in the laboratories of 67 preceptors selected from the core faculty of the UNC Lineberger Comprehensive Cancer Center (UNC-LCCC), are in the 6 established basic research programs in Molecular Carcinogenesis, Virology, Cancer Cell Biology, Immunology, Molecular Therapeutics and Cancer Genetics. Faculty from 25 departments, programs and curricula participate in the training program. All 67 preceptors have independent peer-reviewed research support; total yearly support (direct costs) has increased from $12.9 to $20.3 million dollars since the last renewal. There is a strong emphasis on interdisciplinary training, promoted by; the philosophy and organization of UNC LCCC and facilitated by the Center's many shared core facilities used for training. Support for the facilities comes from the Center's core-support grant, which has just been rated outstanding with increased funding for years 31-35, and from the UNC Program in Molecular Biology & Biotechnology. The plan for training of each fellow is individualized upon entry to the program primarily by the preceptor, with input from the Director, Associate Director, Training Committee, and fellow. Specific features are emphasized according to the needs of the trainees, and the progress of each trainee is monitored. Because of the importance of translational research, a subset of the trainees will be physicians interested in basic research as well as selected Ph.D.'s. Specific efforts have been made to recruit minorities successfully to this training program and will continue to expand in the next funding period. The program includes a weekly seminar series, a monthly in-house seminar series given by the fellows, the annual Cancer Center symposium, the annual Postdoctoral-Faculty Research Day, an annual consultant selected by the fellows, special lectures including a mandatory session on ethics, working research program groups, a postdoctoral fellows' committee and new annual awards for the best papers. The program, administered by the Director & Associate Director with the advice of the Training Committee & the Center's Program Planning Committee, is coordinated and implemented through the Center's Training and Education Office. UNC LCCC will continue to expand in the next 5 years. The present request (22 slots in years 31 and 32 and 24 slots in years 33, 34 and 35) meshes with this backdrop. It is based on the significant expansion in number of outstanding preceptors; solid growth in faculty funding; a major expansion of facilities of the Center, recent and projected; and an increase in highly qualified applicants-all coupled with the further maturation of the training program during the last 5 years and the consolidation of UNC LCCC's national reputation for excellence cancer research and training.