ABCG2 and Alzheimer disease: For instance, in AD, alterations of ABC transporters such as ABCA1, ABCA7, ABCB1, ABCC1, and ABCG2 have been associated with the impaired clearance of amyloid-β (Aβ) peptides, leading to their accumulation in the brain and vessel walls and the formation of neurotoxic plaques or cerebral amyloid angiopathy (CAA) [11,12,13,14,27,28,29,30].