NT5C1A and inclusion body myositis: Although the analysis of anti-cN1A-positive versus anti-cN1A-negative IBM patients showed no correlation with age, duration of symptoms, weakness, antinuclear autoantibodies or MSA or MAA status, the rarity of anti-cN1A in PM and DM patients led to the consideration of autoantibodies as a key marker for differentiating myositis subtypes.