PROJECT SUMMARY/ABSTRACT This application is the competitive renewal of the “Immunobiology of Rheumatic Diseases” Training Program at Washington University School of Medicine. The program, which was initiated in 1977 by Dr. John Atkinson, has a strong record of training postdoctoral fellows who are committed to careers in rheumatic disease research. The goal of the training program is to develop independent scientist who will ultimately work to improve outcomes of patients suffering from rheumatic diseases. The current application, which seeks support for five MD, MD/PhD, or PhD postdoctoral trainees per year, incorporates a number of new programmatic features to enhance this training mission. The Program accepts trainees from an expanded pool of outstanding applicants and benefits from close relationships to the Physician Scientist Training Programs in both Medicine and Pediatrics, the Institute of Clinical and Translational Sciences, and the Division of Biology and Biomedical Sciences. New to this competitive renewal is the offering of a clinical/translational research track which complements our basic science research track. Trainees will benefit from extensive didactic offerings leading to a Master of Science in Clinical Investigation degree. The centerpiece of either track remains an intense mentored research experience. Trainees are mentored by a committed primary faculty mentor, in collaboration with their scholarship oversight committee. The talented group of 35 well-funded faculty mentors are organized into four thematic areas- Immune Regulation and Host Defense, Animal Models of Rheumatic Disease, Clinical/Translational Research, and Omics. These preceptors are a major strength of this grant. The uniquely collaborative environment among the faculty preceptors and at WUSM provides an ideal setting for the professional development of the trainees. Hands on workshops, research seminars and programs in the Responsible Conduct of Research complement the four thematic areas.