ABCG2 and Alzheimer disease: Conflicting reports have also been published for changes in ABCG2 expression in brain specimens from individuals with AD and/or CAA (Xiong et al., 2009; Wijesuriya et al., 2010; Carrano et al., 2014; Kannan et al., 2017; Storelli et al., 2021) and associations between ABCG2 variants and the risk for developing AD (Cascorbi et al., 2013; Fehér et al., 2013).