The use of TCZ in myositis proposed in this protocol is supported by the aforementioned rationale and its efficacy in other rheumatologic disorders. Patients with refractory polymyositis (PM) were treated with tocilizumab and responded favorably. In dermatomyositis, tissue inflammation implicates soluble cytokine networks contributing to disease pathogenesis. Work on a mouse model of myositis noted IL-6 as a mediator of muscle inflammation. Other investigators studying peripheral blood samples and clinical data on both adult and juvenile dermatomyositis (DM) noted that serum levels of IL-6 were significantly correlated with disease activity. In this same study, correlations between serum IL-6 levels and both the type I interferon gene and chemokine signatures were also identified in DM. These authors suggest that the coordinated dysregulation of IL-6 production and Type I interferon signaling implicates these pathways as contributing to disease pathogenesis in DM.