Among the 118 patients diagnosed with IIM, 61 had anti-MDA5+ DM, 20 had anti-MDA5− DM, 22 had anti-synthetase syndrome (ASS), six had polymyositis (PM), and nine had IMNM (immune-mediated necrotizing myopathy). The gene discussed is IFIH1; the disease is acquired idiopathic inflammatory myopathy.