Recently Sun et al. successfully developed an assay measuring active MMP-3 detection in human serum and found that serum active MMP-3 only correlated with inflammatory markers CRP and ESR, but not to other measures of disease burden in RA (DAS, HAQ) which implies that active MMP-3 reflects other aspects of disease than total MMP-3 [36]. This evidence concerns the gene MMP3 and rheumatoid arthritis.