As the initial treatment of RPILD patients with anti-MDA5 Ab-positive DM, a combination of corticosteroids, cyclophosphamide, and calcineurin inhibitor is recommended.[5] However, some of these patients have poor prognoses despite this intensive treatment.[5] More effective treatments for RPILD patients with anti-MDA5 Ab-positive DM are strongly desired. This evidence concerns the gene IFIH1 and dermatomyositis.