IFIH1 and myositis disease: When evaluating Siglec-1 expression induced by JDM plasma or DM serum in relation to myositis-specific autoantibody profiles, we observed the highest levels in anti-NXP2+ (n = 5), anti-MDA5+ (n = 1) and anti-TIF1y+ (n = 4) patients (Supplementary Fig. S5, available at Rheumatology online).