The proposed program is designed to train physicians interested in biomedical research in the area of the rheumatic diseases. The training program will consist primarily of a laboratory experience under the close supervision of a preceptor working on immunologic, molecular biologic, or biochemical problems relevant to the rheumatic diseases. A period of clinical experience will be offered in rheumatology. All trainees will take a course in scientific ethics and a course in scientific methodology. Other formal academic course work is available for those interested but will be at the discretion of the trainee and preceptor. Trainees will generally be physicians who have completed one year of internship and two or more years of housestaff training, usually in general internal medicine. Trainees will be chosen on the basis of their prior academic performance and record of housestaff achievement. Preference will be given to those with acknowledged research interest and demonstrated capacities in research. Four postdoctoral fellows will be selected to participate in the three-year fellowship. At the completion of training, they will be prepared to compete successfully for full-time academic positions in medical schools or research institutes. They anticipate that the majority will operate as rheumatologists within departments of medicine. The primary training unit will be the Rheumatology, Allergy and Immunology Division, Department of Medicine, University of California; and San Diego, School of Medicine. Training can be obtained in research laboratories located at the Basic Science and Clinical Sciences Buildings located in La Jolla or the San Diego Veterans Administration Medical Center also located in La Jolla. Inpatient and outpatient facilities are available at the UCSD Medical Center, the VA Medical Center, and the Thornton Hospital. The first two hospitals have, in addition, a Clinical Research Center for hospitalization of patients participating in investigational programs.