TRIM21 and myositis disease: Serology demonstrated the presence of anti-Ro-52/TRIM21 (high positive), but no myositis-specific, SSc-specific or SSc-overlap autoantibodies were found on line immunoassays (Euroimmun AG, Luebeck, Germany) or on Protein A-assisted immunoprecipitation using radiolabeled K562 cell extracts (Fig. 3).