Objective: To compare the diagnostic utility of laboratory variables,including matrix metalloproteinase-3 (MMP-3), anti-cyclic citrullinated peptide(CCP) antibodies, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR),and C-reactive protein (CRP) inpatients with erosive and non-erosive rheumatoid arthritis (RA). The gene discussed is CRP; the disease is rheumatoid arthritis.