IL12B and inflammatory bowel disease: However, based on the results of this study, the strength of a potential association of IL12B with IBD is several log-fold weaker than that shown for IL23R in our cohort [6] and other major CD susceptibility genes such as NOD2 and ATG16L1 (Supplemental Table S3), suggesting a more important role for IL-23R than IL-12/23 p40 in the genetic susceptibility to IBD.