Anti-TNF therapies used in IBD have been shown to be effective but there is a 20–30% primary non-response rate (Ford et al., 2011) and the annual risk of loss of response to anti-TNF is 13% per patient-year for Infliximab (Gisbert and Panes, 2009) and 20% per patient-year for Adalimumab (Billioud et al., 2011). This evidence concerns the gene TNF and inflammatory bowel disease.