Conversely, knocking down OSCAR in mice that were developing DMM-induced OA significantly ameliorated OA14: joint histology at 9 weeks of mice that underwent weekly IA-injections with small-hairpin OSCAR-expressing adenovirus (Ad-shOSCAR) starting 1 week after DMM surgery revealed marked improvements in their severe cartilage destruction (as indicated by Osteoarthritis Research Society International [OARSI] grading), osteophyte maturity, SBP thickness, and synovitis. The gene discussed is OSCAR; the disease is synovitis.