PTPN22 and Cowden disease: After Bonferroni correction for multiple testing both the homozygous and the heterozygous variant genotypes of IL23R G>A (rs11209026) (ORadj: 0.38, 95% CI: 0.21–0.67, p = 0.03) and PTPN22 1858 G>A (rs2476601) (ORunadj: 0.54, 95% CI: 0.41–0.72, p = 7*10−4) were associated with reduced risk of CD.