IL13 and synovial sarcoma: One major limitation of our study entails that the scarce volume of subacromial fluids (0.5 mL and 1 mL, at most, from stiff and non-stiff shoulders, respectively [3]) did not allow for comparison of the concentration of IL-6, IL-10, and IL-13, recognized leptin-suppressed cytokines, between SS and non-SS groups by ELISA assay.