Impairment of normal physiological function of BBB is often found in AD brain, such as crosstalk between neuroinflammation and reduced BBB stability, which is maintained in normal state, whereas in AD brain, the increased permeability of BBB allows the opportunity for peripheral inflammatory factors to enter the brain, which in turn is overexpressed by AD, possibly via NF-kB pathway (Vest and Wyss-Coray, 2022). This evidence concerns the gene NFKB1 and Alzheimer disease.