Tumour necrosis factor (TNF) antagonists such as the anti-TNF monoclonal antibodies (mAbs) infliximab (Ifx) and adalimumab (Ada) and the soluble TNF receptor etanercept (Eta) are efficacious in several immune-mediated inflammatory diseases (IMIDs), including rheumatoid arthritis (RA), spondylarthropathies (SA), Crohn's disease (CD), psoriasis arthritis, and juvenile arthritis [1-8]. The gene discussed is TNF; the disease is Crohn disease.