background in some autoimmune diseases such as rheumatoid arthritis (ra), interleukin-27 (il-27) and il-33 levels are increased. these observations suggest that il-27 and il-33 may have a role in the pathogenesis of polymyositis/dermatomyositis (pm/dm). conclusions these data indicate that il-27 might be selectively involved in the pathogenesis of dm and pm. however, il-33 does not appear to be...