(1) To assess the predictive value of anti‐tissue transglutaminase immunoglobulin A (IgA) antibodies (a‐tTG) by chemiluminescence immunoassay (CLIA) related to duodenal histology in children with suspected celiac disease (CD) and (2) to determine the cut‐off value of a‐tTG by CLIA that allows diagnosis of CD avoiding biopsy. Here, TGM2 is linked to Cowden disease.