Another member of the tenascin family, Tenascin C (Tnc), was recently shown to be an endogenous activator of TLR4, an inducer of IL-6 and TNFα, and was required for joint damage in arthritic mice [48], suggesting that Tnn could have a function similar to Tnc in arthritis. The gene discussed is TNN; the disease is arthritic joint disease.