ROC analysis identified specific markers highly sensitive for RA but not PsA, these included sICAM-1, MMP1, MMP3, PP and c-Peptide, therefore we believe that measuring these markers, together with the classical CRP and SAA, could aid in discriminating RA from PsA diseases, thus helping with diagnosis and specific treatment. The gene discussed is MMP3; the disease is rheumatoid arthritis.