In a mouse model of PM, C protein-induced myositis (CIM), the pathology reportedly mimics that seen in human PM. Mice were treated with anti-IL-6 receptor monoclonal antibodies or control antibodies and muscle tissue was histologically and immunohistochemically analyzed. CIM was ameliorated in this mouse model implicating IL-6 in the development of myositis. These results not only identified this model as useful to understanding PM but they suggest that IL-6 blockade be considered as a new therapeutic approach in the treatment of myositis.