The Connective Tissue and Diseases Section began studying inflammatory myopathies (polymyositis, dermatomyositis, and related diseases) some years ago in an attempt to understand the relationship of autoantibodies to autoimmune disease. These diseases seemed to offer the best example of autoimmune diseases associated with highly specific disease-related autoantibodies and evidence of a viral etiology. They are very uncommon and hence relatively less studied than other autoimmune diseases, and they are very debilitating and hence in need of improved therapy. In order to attract patients here to allow more detailed clinical, immunological, genetic, and viral studies, we began doing trials of therapy and have completed a number of such studies. They are among the very few published controlled trials in this difficult to treat family of illnesses.