To model Alzheimer's disease (AD), Shin et al. combined a BBB chamber seeded with human cerebral microvascular endothelial cells, forming tight monolayer at the interphase of collagen scaffold with a cell chamber with either wild type (WT) ReNell VM human neural progenitor (ReN) cells or ReN cells with familial Alzheimer's disease mutations in APP gene and APP/PSEN1 genes.226. The gene discussed is PSEN1; the disease is Alzheimer disease.