Abatacept concentrations resembling serum concentrations in patients with RA treated with abatacept significantly inhibited the production of TNF-α (−77%), IL-1β (−65%), IL-6 (−83%), IL-8 (−83%), and CCL2 (−71%) by monocytes stimulated with ACPA. The gene discussed is IL6; the disease is rheumatoid arthritis.