PRB1 and acquired idiopathic inflammatory myopathy: Numerous autoantibodies may be associated with IIM, e.g., antisynthetase antibodies, myositis-specific antibodies, and myositis-associated autoantibodies, including anti-Ro/SSa, anti-U1RNP 70 kDa, anti-PM/Scl 75 and 100 kDa, and anti-Ku antibodies [12].