There are exceptions with odds ratios of 3.9 and 2.5 reported for variants of NOD1 and IL23R on the risk of inflammatory bowel disease (IBD) (Barrett et al., 2008) while the distribution of effect sizes for the remaining 69 variants associated with Crohn's disease ranged from 1.04 to 1.74 (Franke et al., 2010). Here, IL23R is linked to inflammatory bowel disease.