In combination with a well-defined set of clinical features, a panel of biomarkers is routinely used both in the diagnosis of RA (for example, the presence of rheumatoid factor and/or anti-citrullinated peptide (CCP) antibodies in serum) and the monitoring of disease progression (for example, C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR)). The gene discussed is CRP; the disease is rheumatoid arthritis.