APOA1 and Alzheimer disease: With the increasing reports of the correlation between AD and APOA-I in clinical patients, as well as preclinical studies on the transport of APOA-I to cross the BBB and BCSFB, this multifunctional apolipoprotein, which integrates lipid metabolism regulation, vascular protection, neuroprotection, anti-inflammatory, and antioxidant properties, has begun to garner significant attention.