In a recent study the diagnostic performance of the Anti-cN-1A ELISA [EUROIMMUN, Lübeck, Germany] was evaluated by two reference laboratories using different serum panels.18 The first cohort consisted of a total of 286 sera from patients with clinically and pathologically diagnosed definite sIBM, patients with suspected sIBM, myositis controls, non-myositis autoimmune controls and healthy subjects. Here, NT5C1A is linked to myositis disease.