However, most of those reports showed that the prevalence of CADM is ≤40% in other East Asian countries, suggesting that this prevalence of anti-MDA5 Ab-positive CADM is much lower than that of Japan.[14–17] In North America, the prevalence of CADM is approximately 50%, whereas the prevalence of RPILD is approximately 20%, indicating that the prevalence of RPILD with anti-MDA5 Ab-positive is much lower than that of Japan.[18,19]. Here, IFIH1 is linked to clinically amyopathic dermatomyositis.