We previously suggested that matched subscapularis tendon from patients with full thickness rotator cuff tears may be a model of early human tendinopathy based on histological appearances and significantly increased levels of cytokines and apoptotic markers in these tissues.13 The purpose of this study was to formally assess the expression of HMGB1 within this human model of tendinopathy and thereafter explore the mechanistic activities of HMBG1 on inflammation and matrix production in tenocytes in vitro. This evidence concerns the gene HMGB1 and disease of the tendon.