In a pre-clinical APOE4;5xFAD mouse model of AD, it has been shown that APOE4 induces a loss of capillary pericytes coverage in hippocampus and brain cortex regions, linked by a decrease of ZO-1 and occludin expression in tight junctions between endothelial cells forming the BBB [142]. The gene discussed is APOE; the disease is Alzheimer disease.