Althoughwe have previously associated polymorphisms in several genes includingNOD1&2, TLR4, DLG5, ATG16L1, and IL23R with risk of IBD in New Zealand[6–12], these only increase the IBD risk to a small extent and cannotexplain the high New Zealand disease incidence.For example, carrying the common NOD2 1007-femtdsecond mutation increased the riskof CD 4.4 fold (95% confidence interval 1.6–12) [12]. Here, ATG16L1 is linked to inflammatory bowel disease.