ABCG2 and Alzheimer disease: Samples from AD patients showed no changes in ABCG2 protein expression in the hippocampus and another study reported that ABCG2 was not involved in Aβ42transport of ABCG2 in hAPP mice,59in contrast to these studies, the expression of ABCG2 mRNA and protein levels compared with control, it has been reported to increase significantly in AD/CAA patients.60In a study designed to determine the action of ABCG2 in AD, greater Aβ accumulation was found of ABCG2 knockout animals injected with Aβ than in control mice.