TGM2 and celiac disease: The current diagnostic algorithm for coeliac disease is a two-step approach that starts with serological testing for IgA tissue transglutaminase (IgA-tTG) and endomysial antibodies (EMAs) of patients with clinical suspicion of coeliac disease and first-grade relatives of patients with confirmed coeliac disease, followed by endoscopy and duodenal biopsies in those with positive serological results [6].