MGAT3 and Alzheimer disease: Our finding that bisecting GlcNAc was generally increased in Alzheimer’s disease is consistent with an upregulation of the sole synthesizing enzyme for this epitope (N-acetylglucosaminyltransferase III), which has been reported to be the case in Alzheimer’s disease.38 However, levels of specific glycopeptides may be more specific markers for Alzheimer’s disease pathology.