To exclude additional major variants in the gene region and possible LD of the identified promoter SNPs to other potentially functional variants in the TCF-4 gene, we sequenced known coding exons, with ∼100 kb overlapping intron boundaries in 10 randomly chosen controls (6 identical to promoter analysis) as well as 25 patients with ileal CD (7 identical to promoter analysis) (Figure S1). Here, TCF4 is linked to Cowden disease.