IFIH1 and dermatomyositis: Even though anti-MDA5-positive DM is not associated with an increased risk of malignancy (0–4%) (38), an interesting finding in our study is that 33% of patients with anti-MDA5-positive DM in the derivation cohort and 76% of the validation cohort showed slight elevation of CEA, and positive CEA was the independent risk factor for 6-month mortality.