PTGS1 and rotator cuff syndrome: It has been described that inflammatory cytokines, such as SDF-1, IL-1β, TNF-α, TGF-β, and IL-6 as well as pain-associated mediators (cyclooxygenase 1 (COX-1) and 2) and proteolytic enzymes (matrix metalloproteases (MMPs)) are increased in subacromial bursae from patients with rotator cuff tear or frozen shoulder compared to healthy controls [14,53,72,73,74,75,76,77,78].