Inclusion of all 13 myokines in simple linear regression showed a significant positive association between IFNα-treated myobundles and JDM patients, in media and sera myokine values (R2 = 0.48, padj=0.02), yet no significant relationship between IFNβ-treated or poly(I:C)-treated myobundles with JDM patients (Supplementary Figure 2). Here, IFNA1 is linked to juvenile dermatomyositis.