ABCB1 and Alzheimer disease: Nevertheless, several recent clinical efforts utilizing current and emerging advanced analytical methods (e.g., proteomics) coupled with diagnostic neuroimaging studies (e.g., PET scans, magnetic resonance imaging (MRI)) have significantly improved our understanding and appreciation of the role of specific BBB transporters in certain neurological diseases such as AD where specific transporters such as ABCB1 play a role in the disease pathology.