TLR4 and disease of the tendon: Levels of HMGB1 are upregulated in the synoviocytes and fibroblasts in response to injury or inflammatory stimuli.29 Furthermore, blockade of TLR4 signalling is able to partially reverse the proinflammatory tenocyte phenotype in vitro raising the possibility of TLR4 blockade as a therapeutic entity in human tendon disease.