Celiac disease is an autoimmune enteropathy caused by harmful immune reactions to cereal gluten proteins.1 The enzyme transglutaminase 2 (TG2) is involved in the pathogenesis both by being the target of highly disease-specific autoantibodies and by deamidating gluten peptides, thereby allowing their presentation to T cells by HLA-DQ2 or HLA-DQ8 molecules. The gene discussed is TGM2; the disease is celiac disease.