This competing renewal of a training program is designed to prepare highly qualified postdoctoral fellows for research leadership careers in translational lung biology and pathobiology. To ensure the most competitive program, we will seek applications from MD and PhD candidates from a wide range of sources and a wide variety of scientific, personal and ethnic backgrounds emphasizing a nationwide competition. This program has been highly successful since its inception 20 years ago, and in this round we have maintained our focus on training in fundamental areas relevant to lung inflammation, injury, immunology, and repair. We have also added and strengthened investigative efforts that will foster human and translational investigations and training in cutting edge approaches including proteomics, genomics, computational biology, and genetics. MD trainees may enter this program only after having completed the clinical requirements for Board eligibility. Optimal research training is achieved by protecting the trainees' time to allow their efforts to be dedicated to research. Training is mentor-based, interdisciplinary, and enriched by didactic courses and by interactions with diverse faclty who are recognized experts in their fields. Mentors are chosen based on proven ongoing quality and productivity of their research programs, significant extramural support, and availability and commitment to serve as mentors. The mentors are amongst the leaders of Yale research and belong to research spheres identified as important in respiratory disease processes: including cell and molecular biology, genetics, genomics, immunology, inflammation, tissue remodeling, clinical epidemiology, biostatistics, human investigation and translational biology. Because of the wide spectrum of outstanding laboratories at Yale and the institutional nature of this proposal, 8 postdoctoral positions are requested per year. The program will be a minimum of 2 years. Trainee progress will be carefully evaluated and productivity monitored by each mentor, a Research Advisory Committee, and the Program Directors. The uniqueness of this program stems from a) the truly institutional nature of this grant involving 4 Schools, 3 Clinical Departments (Pediatrics, Interna Medicine and Psychiatry) and 9 Basic Science Departments (Immunobiology, Molecular Biology and Biophysics, Pharmacology, Cell Biology, Physiology, Biology, Genetics, Laboratory Medicine and Pathology)~ b) the strong interactions that exist between the clinical and basic science faculty on this program~ and c) the training track record of the mentors.