IL1B and myositis disease: There are also reports of persisting inflammatory cells and increased expression of IL1 in muscle tissue despite long-time treatment with high doses of GC.3, 24 Intra-articular treatment with GC significantly reduces mPGES-1, COX-1 and COX-2 expression in the synovial tissue from patients with rheumatoid arthritis and is associated with clinical improvement.25 Whether mPGES-1 and COX expression in skeletal muscle from patients with myositis is affected by immunosuppressive treatment has not been investigated to date.