UCN2 and dermatomyositis: To our surprise, anti-MJ antibodies were the most prevalent specificity (10/58; 17%) in our PM/DM patients, followed by anti-Jo-1 (10%), -PM-Scl (10%), -U1RNP (7%), -p155/140 (5%), -SRP (5%), -EJ (3%), -Mi-2 (2%), and -OJ (2%).