Even if strongly suggestive, the role of anti-HMGCR in pathogenesis of immune-mediated necrotizing myopathy has not been formally demonstrated, although statins upregulate muscle HMGCR expression in anti-HMGCR positive myopathy patients [135], anti-HMGCR induce muscle atrophy [64], and their plasma levels correlate with both circulating CK and stage of activity of the disease [138]. This evidence concerns the gene HMGCR and muscle atrophy.