We have one overarching goal: Train postdoctoral fellows who will be qualified and well-positioned to lead in the development, implementation, dissemination, and application of research-based tobacco control, public health, policy, and clinical practice. Specifically, we propose to continue support of a two- year postdoctoral fellowship that will attract individuals with a strong commitment to transdisciplinary research from a wide variety of backgrounds from medical, biological, social, behavioral, and policy sciences to help build the next generation of scientific leaders in tobacco control. Tobacco remains the leading preventable cause of death in the U.S. and it is responsible for 35% of all cancer deaths. The need for such experts continues to grow as science is needed to inform actions taken by the Food and Drug Administration to regulate tobacco products, to address the rapid emergence of new tobacco products like electronic cigarettes, to guide the implementation of health care reform with an emphasis on disease prevention, and to influence the implementation of the Framework Convention on Tobacco Control, the first public health treaty negotiated under the auspices of the World Health Organization. Our program embodies the innovative cancer prevention training needed to give young scientists the tools to conduct and communicate transdisciplinary research by active involvement in multiple disciplines and translation of science to policy and clinical practice. We provide transdisciplinary coursework in tobacco science, health policy, biostatistics, tobacco policy, prevention and treatment of addiction and tobacco-related disease, combined with research directed by primary and secondary mentors from different disciplines. Fellows complete a course where they prepare and submit grant proposals to external funding agencies for their third year of fellowship. Research mentors include 33 faculty with active research programs from all four schools at UCSF (Medicine, Nursing, Pharmacy and Dentistry). Mentors' research programs span tobacco control policy, the tobacco industry as a vector for cancer and other diseases, tobacco marketing, tobacco addiction and its prevention and treatment, health effects of smoking and secondhand smoke exposure, smokeless and emerging tobacco products, and smoking cessation. The wide variety in backgrounds and interests of fellows housed in the UCSF Center for Tobacco Control Research and Education provides a strong transdisciplinary environment that creates continuous opportunities to learn from colleagues working in other disciplines. Each fellow's individual development plan is created by the fellow, and reviewed by both mentors and the Fellowship Advisory Committee. The Committee also selects fellows from a competitive national pool: in the current funding period we had 159 applications for 25 positions. We have an outstanding track record of success: during the current funding period our fellows produced 120 papers in 69 different peer reviewed journals. Of the 29 postdoctoral fellows who have completed training, 26 (90%) have active scientific careers and 16 (55%) of graduates are academic faculty.