It has been demonstrated that aberrant methylation in the promoter region of the MGAT3 gene (encoding the MGAT3 enzyme responsible for the production of bisecting GlcNAc structures) results in an increased percentage of bisecting GlcNAc on IgG glycans in CD patients, suggesting a possible involvement of bisecting GlcNAc in the pathogenesis of CD (168). The gene discussed is MGAT3; the disease is Cowden disease.