,29,30 Perturbations in PC metabolism appear to play a role in several key molecular pathways intrinsic to cognitive decline and Alzheimer’s disease including neuroinflammation through arachidonic acid signalling, amyloid precursor protein processing through phospholipase A2, and cholesterol transport through high-density lipoproteins.31–33. This evidence concerns the gene APP and early-onset autosomal dominant Alzheimer disease.