Regulation different network analysis of rheumatoid arthritis (RA) and osteoarthritis (OA). 
Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovitis that progresses to destruction of cartilage and bone.  The purpose of this study was to employ microarray analysis combined with bioinformatics techniques to evaluate differential gene expression in BM-derived mononuclear cells obtained from patients with rheumatoid arthritis (RA) or osteoarthritis (OA) to study the pathogenesis of this disease.  Gene expression profiles in BM-derived mononuclear cells from 9 RA and 10 OA patients were obtained from GEO.  The bone marrow (BM) mononuclear cells showed 2581 up-regulated and 649 down-regulated genes in RA patients relative to the OA group: Our analysis indicated that several differentially expressed genes might play crucial roles in RA development, including SP1, RARA, ETS1, ETS2, FOS and ESR1.  Further analysis predicted these genes might be involved in RA through cancer related pathways and immunity related pathways.  Furthermore, these genes may serve as novel therapeutic targets for the treatment of RA.