Of the 19 patients that had refractory anti‐MDA5 antibody‐positive CADM with rapidly progressive interstitial pneumonitis treated with a combination of increasing tacrolimus trough concentration‐escalating dual therapy, 16 displayed decreased ferritin and lactate dehydrogenase levels, an improved oxygenation index, and improved high‐resolution lung CT findings. The gene discussed is IFIH1; the disease is Interstitial pneumonitis.