“Biology of the Lung: A Multi-Disciplinary Approach” has been the title and theme of this T32 since it began in 1975. For years 46-50, we propose to train 6 predoctoral PhD candidates and 6 postdoctoral fellows (3 PhD and 3 MD) per year in lung biology research, in the only T32 providing lung science training at Boston University. Our overarching goals are: 1) To train the next generation of PhD and MD scientists in 3 scientific foci (SFGs) that are special strengths at BU: lung Development & Regenerative Medicine, lung Infection & Immunity, and lung Biomedical Data Sciences; 2) To use multidisciplinary approaches (including these SFGs) to enhance the training environment, enrich the learning experiences of trainees, and better prepare our graduates for careers in lung science; and 3) To imbue in our trainees, in particular women and those from under-represented groups (URGs), the importance and excitement of discovery and creation of new knowledge that will improve the lung health of all populations, especially the at-risk populations we serve, through didactic and highly interactive courses and seminars. These 3 goals encompass all of the 6 NHLBI strategic trainings guidelines. We will provide exemplary training by exceptional faculty mentors from 7 departments across 3 schools in order to establish expertise in 11 discipline-specific core competencies that we have designed in lung biology broadly, and specifically in the areas of regenerative and reparative medicine, “omics”/computational biology, immunology/infectious diseases, and population studies including comparative effectiveness and outcomes research. The Boston University environment is ideal for recruiting, advancing, and retaining URG trainees from diverse backgrounds, as evidenced by its 145 year history of training URG scholars and our successful T32 track record. Our T32 faculty have designed unique trainings in the responsible conduct of research and created new programs for recruitment and retention of scientists from URGs that have been adopted school-wide. The keystone principle of our training program is bi-directional translation of ideas between basic and clinical spheres. This is why we train MD fellows together with PhD post-doctoral fellows, MD/PhD students, and PhD students in a unified program which includes a unique weekly Combined Clinical and Research (CCR) conference where all our basic researchers, physician scientists, educators, and clinicians interact. Our current program plan represents the very best we have offered in over 45 years of training exceptional lung researchers and international pulmonary medicine thought-leaders, including numerous Deans, Department or Division Chairs, Center Directors, and Industry leaders, on track to produce the next generation of trail-blazers in multidisciplinary lung science.