Our aim is to analyze the number and distribution of circulating monocytes, and of their CD14+highCD16-, CD14+highCD16+ and CD14+lowCD16+ subsets in methotrexate (MTX) non-responder patients with RA, and to determine their value in predicting the clinical response to adalimumab plus MTX treatment. The gene discussed is CD14; the disease is rheumatoid arthritis.