This is the 45th year of this highly successful research training program in Rheumatology at the Massachusetts General Hospital (MGH) and Harvard Medical School (HMS), supported by this training grant. The goal of this program is to train MD, MD/PhD and PhD post-doctoral fellows for independent investigative careers in rheumatology research. Of the 67 trainees who were supported by this training grant, many now have faculty appointments in academic medical centers, including holding current or prior leadership positions at major institutions as Deans, Presidents, CEOs, Scientific Directors, and Division Chiefs. Our program centers on our outstanding clinical Rheumatology fellowship and our strong basic, translational, clinical science and clinical epidemiology research programs. The MGH Rheumatology T32 Training Program is situated within a vibrant, technologically-innovative research environment. Our program provides supervised laboratory, clinical and health outcomes research under the guidance of accomplished faculty members, as well as structured training in rheumatology, immunology, clinical trials, epidemiology, biostatistics and ethical issues through courses and conferences. The basic science focus of the program is the immunopathogenesis of rheumatic disease. Areas of particular interest include autoimmunity, tolerance, innate immunity, leukocyte trafficking, infectious causes of rheumatic diseases, systems immunology, fibrosis, and cartilage and bone biology. Disease areas of particular interest include rheumatoid arthritis, lupus, gout, scleroderma, Lyme, vasculitis and IgG4-related disease. The clinical science research program focuses on population and health care sciences in rheumatic diseases. This application requests 5 training positions that will be allocated to trainees who are committed to at least 2 to 3 years of research training. Candidates will be drawn from the MGH Rheumatology fellowship and from post-doctoral trainees already working in the laboratories of faculty mentors. Twenty-two faculty members primarily from the MGH Rheumatology Unit and its affiliated Center for Immunology & Inflammatory Diseases (CIID) participate in this T32 Program. Faculty mentors were carefully chosen based on their track record of publications, grants, mentoring, collaboration and mutual research interests. The training program also leverages many MGH research centers, including the Ragon Institute, Center for Cancer Research, Center for Regenerative Medicine, and Mongan Institute. The MGH provides an outstanding training environment and is home to the largest hospital-based research enterprise in the U.S., with an annual budget nearly $2 billion comprising more than 9,500 researchers. Opportunities at Harvard University, including course work and the NIH-funded Harvard Clinical and Translational Science Center as well as the Harvard T.H. Chan School Public Health and the Broad Institute provide additional resources for trainees. In sum, in...