Rheumatoid arthritis (RA) is a chronic inflammatory disease resulting in inflammation of the synovial lining and destruction of the adjacent bone and cartilage. Although the initiating event of RA is still unknown, recent research has demonstrated the importance of the increased production of tumour necrosis factor (TNF) α in the perpetuation of the inflammatory process of this disease. Targeting this molecule with soluble receptors—that is, etanercept, or antibodies, like infliximab or adalimumab, a new class of highly effective antirheumatic drugs has been developed. Unfortunately, not all patients respond sufficiently to TNF blockade or become unresponsive, and therefore …