Intra-articular NBD treatment results in decreased pro-inflammatory cytokine expression. Shown are representative overview images of mutant NBD (MUT)-treated ankle joints. Expression of different cytokines was evaluated by immunohistochemical staining of paraffin-embedded ankle joints. Detailed images of synovial cytokine staining are provided (boxes in upper panels indicate synovial tissue location), followed by results from digital image analysis (n = 10/group). Tumor necrosis factor (TNF)-α and interleukin (IL)-1-β expression was significantly reduced in the NBD-treated group as compared with the MUT-treated group (*p = 0.05 and *p = 0.04, respectively). Data represent mean ± standard error of the mean.