R381Q (rs11209026), the only coding IL23R variant identified by GWAS, confers an OR of 0.45 for Crohn's disease development (MAF 1.9% in CD, 7% in controls) [4], and an OR of 0.55 for UC development (MAF 3.7% in UC, 7% in controls) [15], implying a protective effect. Here, IL23R is linked to Crohn disease.