2. An established diagnosis of polymyositis, dermatomyositis, juvenile polymyositis/dermatomyositis, myositis associated with other collagen diseases. Diagnosis requires electrophysiological studies and histopathologic features. MRI evidence of muscle inflammation or histological evidence of active myositis is mandatory at entry. If patient had dermatomyositis/polymyositis associated with malignancy, the patient has to be free of malignancy for 5 years and considered to be cured.