CHD4 and myositis disease: Testing for myositis-related autoantibodies in a subset of 75 sIBM sera revealed reactivity against Ro-52 in 14.7%, against PL-7, PL-12, SRP and Ku in 4% each, against TIF1γ in 2.7%, and against OJ, EJ, Jo-1, PM-Scl75, PM-Scl100, and Mi-2β in 1.3% each (Table 3).