To clarify the question of dependency of the MMP/TIMP production, the gene expression data of CSP cultured with synovial fluid (ND, OA or RA) showed that the mRNA level is decreased for MMP1 and MMP3 during cultivation of CSP treated with OA-SF and RA-SF compared to CSP treated with ND-SF. This evidence concerns the gene TIMP1 and rheumatoid arthritis.