ABCB1 and Alzheimer disease: Additionally, ligands that are substrates of other BBB transport molecules such as P-glycoprotein, an efflux transport protein whose changes in expression are well-characterized with BBB breakdown in AD and neuroinflammation, similarly may demonstrate regional BBB degeneration in patients with AD (van Assema et al., 2012; Deo et al., 2014; Raaphorst et al., 2017; Savolainen et al., 2017; Van Dyken and Lacoste, 2018; García-Varela et al., 2021; Garcia-Varela et al., 2022).