IFIH1 and juvenile idiopathic inflammatory myopathy: In this study, we explored the prevalence of anti-MDA5 autoantibodies among 59 JIIM patients in Chinese cohort and summarized the clinical and histopathological characteristics as well as treatment outcomes of these 3 anti-MDA5-positive patients to improve the early diagnosis and the precise treatment of Chinese anti-MDA5-positive JIIM patients.