APOE and Alzheimer disease: Byusing iPSC-derived BBB cells from patients with ApoE polymorphisms, Aβaggregation was amplified.89 In this study, the ApoE4/4 genotype showed the most dramatic Aβaggregation when iPSC-derived BBB cells were cultured in Aβ conditioned medium.Most recently, microfluidic devices have been used to study AD, specificallywith human BBB-on-a-chip models to identify AD biomarkers and pathogenicmechanisms by introducing Aβ directly, or by introducing a mutation to ADneurons to overproduce Aβ.