TLR4 and myositis disease: In fact, muscle biopsies of myositis patients show a significantly increased expression of TLR-2, TLR-3, TLR-4, and TLR-9 in the skeletal muscle and infiltrating cells as well as the enhanced expression of cytokines such as IFN-γ, IL-4, IL-17, TNF-α, IL-6 and type 1 IFNs.