NOD2 and inflammatory bowel disease: Investigating the two well-known IBD genes prioritized in our analyses, NOD2 had higher significance in the CD-specific SKAT-O analysis (P = 9.51 × 10−14, Supplementary Fig. 3 and Supplementary Data 2) but was insignificant in the UC-specific analysis (P = 0.85) (Supplementary Fig. 4 and Supplementary Data 3) as expected, since NOD233 is not known to cause UC.