The aims of this study were to do, comparative analysis of the levels of different cytokines such as LIF, TNF-alpha, IL-1, IL-6 and OSM, in the synovial fluid samples aspirated from 10 Rheumatoid arthritis (RA), 25 Osteoarthritis (OA) and 7 Mixed arthropathies (MA) patients. This evidence concerns the gene OSM and rheumatoid arthritis.