Within CADM, the presence of anti-melanoma differentiation-associated protein 5 (anti-MDA5) autoantibodies defines a distinct clinical phenotype strongly linked to rapidly progressive interstitial lung disease (RP-ILD), a life-threatening pulmonary complication with high morbidity and mortality [3,4]. This evidence concerns the gene IFIH1 and clinically amyopathic dermatomyositis.