To explore this, in MSD patients we measured serum levels of markers related to bone turnover, i.e., CTX-I, cartilage oligomeric matrix protein (COMP), OPG, and RANKL, as well as adipokines associated with the pathogenesis of RA and OA, i.e., visfatin, adiponectin, leptin, and resistin. This evidence concerns the gene COMP and rheumatoid arthritis.