The serum aldolase was the most sensitive test to detect the presence of a positive antibody on an extended myositis antibody panel with a sensitivity of 54.5%. The anti-SSA was the least sensitive at 21.4%. A positive result for anti-SSA antibodies was associated with a 100% positive predictive value when all other screening tests (ANA, aldolase, and CK) were also positive. Here, BTG3 is linked to myositis disease.