PTGS2 and Alzheimer disease: Elevated levels of cyclooxygenase-2 (COX-2/PTGS2) and prostaglandins (PGs) are involved in the pathogenesis of AD, COX-2 dysregulation influences abnormal cleavage of the β-amyloid precursor protein, aggregation, and deposition of β-amyloid plaques and the inclusion of phosphorylated tau in neurofibrillary tangles.