IFIH1 and clinically amyopathic dermatomyositis: Dermatomyositis (DM) characterized by amyopathy or hypomyopathy with the typical skin symptoms is defined as clinically amyopathic dermatomyositis (CADM).[1] Among DM patients, antimelanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) has been identified as a new autoantibody.[2,3] It has been widely recognized that anti-MDA5 Ab-positive DM patients frequently develop rapidly progressive interstitial lung disease (RPILD) with poor prognosis.[2,4]