A study [116] investigating EEC subtypes and EEC markers using terminal ileal tissue from patients with (i) active ileal CD (n = 38), (ii) inactive ileal CD (n = 5), and colonic tissue from patients with (iii) active colonic CD (n = 12) (iv) inactive colonic CD (n = 4) and controls (n = 60) reported a 3.3-fold increase in CgA mRNA expression, 3.1 fold increase in GLP-1 expression, a 1.8 fold increase in neurogenin-3 (Ngn-3) gene expression (a transcription factor involved in the epithelial cell differentiation to the EEC lineage) in ileal CD compared with controls. This evidence concerns the gene GCG and Cowden disease.