MUSK and myositis disease: Anti-PM-Scl 75 and anti-signal recognition particle (SRP) antibodies were positive, but no other myositis specific autoantibodies, including Jo-1, ARS, MDA5, TiF1γ, Mi-2, Ku, PL-7, PL-10, OJ, EJ, or MG-related antibodies, including AChR and muscle specific kinase (MuSK) were observed.