Diagnosis of CD is based on elevated serological auto-antibody studies, such as anti-tissue transglutaminase (anti-tTG), anti-endomysial antibody (anti-EMA), and anti-deamidated gliadin peptide (anti-DGP), and confirmed when biopsies of the small intestine obtained via esophagogastroduodenoscopy show histology consistent with villous blunting in addition to crypt hyperplasia and an increase in intraepithelial lymphocytes. This evidence concerns the gene TGM2 and Cowden disease.