This potential pathophysiological role of IFN in DM may explain the symptom improvement experienced by our patient after starting anifrolumab treatment. Anifrolumab has additionally been shown to have a good safety profile when used to treat patients with SLE with up to three years of treatment on background conventional disease-modifying antirheumatic drug (DMARD) therapies. This evidence concerns the gene IFNA1 and systemic lupus erythematosus.