TGM2 and Cowden disease: In this review, we explored all aspects regarding TGs—in particular TG2—in CD, including the consolidated concept of the role of TG2 in disease pathogenesis, the new studies on the coeliac cellular phenotype, the recent discoveries with regard to targeting TG2 as a possible new therapeutic approach, and finally, the use of a food-grade TGm to detoxify gluten sequences.