Given the lack of efficacy of etanercept in treating CD [17] despite its demonstrated efficacy in rheumatoid arthritis and psoriasis and the inability of LMP-420 to ameliorate murine DSS-colitis despite lowering colon TNF levels, the role of direct TNF inhibition in the pathogenesis and/or treatment of inflammatory bowel disease remains undetermined. Here, TNF is linked to rheumatoid arthritis.