APP and Alzheimer disease: Additionally, cholesterol can influence AD progression by regulating the extent of Aβ fibrilization as well as the clearance of Aβ peptides.26Cholesterol levels are positively correlated with the degree of Aβ precursor protein (AβPP) processing, and the levels of cholesteryl esters and free cholesterol can affect amyloid formation.27In conclusion, increasing cholesterol levels effectively prevent or reverse pathological changes associated with AD, including Aβ deposition, synaptic injury, autophagic inhibition, and apoptosis.