IFIH1 and myopathy: In 2005, anti-melanoma differentiation-associated protein-5 (anti-MDA5) was identified as a novel autoantibody by Sato [1], in patients diagnosed with clinically amyopathic dermatomyositis (CADM), which was defined as having a manifestation of typical skin lesions of dermatomyositis (DM) without clear evidence of myopathy.