PROS1 and Alzheimer disease: Alzheimer’s disease (AD) is themost common cause of dementia.AD is characterized by the accumulation of neurofibrillary tangles,fibrillary lesions in the form of neurotic plaques, and dystrophicneurites, which contain hyperphosphorylated, insoluble intracellulartau protein.1 The symptoms and progressof AD are strongly related to the magnitude and location of pathologicalintracellular tau.2 O-GlcNAcylation isa common post-transcriptional glycosylation where intracellular proteinscan be modified by single-sugar O-linked-β-N-acetyl-glucosamine (O-GlcNAc).