While muscle biopsy could not be required for the diagnosis of anti-HMGCR myopathy, as the specificity of the antibody is very high [27], the histopathology has been considered relevant for the prognosis by the European Neuro Muscular Centre (ENMC), since the presence of muscular dystrophy or perifascicular atrophy is useful to better differentiate and subclassify patients with this type of myositis [28]. The gene discussed is HMGCR; the disease is myopathy.