Alzheimer's disease (AD) is a progressive neurodegenerative disorder with no cure and limited treatment options. It is the most common cause of dementia, and its prevalence is expected to double in Europe by 2050 due to the ageing population. Despite significant research efforts, current therapies are limited in their ability to halt disease progression. To tackle this pressing problem, researchers have focused on grasping the pathogenesis of Alzheimer's disease (AD) and creating novel therapies aimed at enhancing the brain's protective systems, such as the blood-brain barrier, while also diminishing the buildup of amyloid-beta (Aβ) proteins. To tackle this pressing problem, the present project has been focused on developing an innovative gene therapy approach aimed at targeting and modulating the blood-brain barrier (BBB) to enhance the overall clearance of Aβ. The proposed Aβ lowering intervention relies on re-establishing proper expression levels of a novel key intervenient in the process of Aβ clearance across the brain endothelium. By delivering such therapeutic genes specifically to the brain endothelium, one aims to: i) restore target gene expression at BBB and enhance brain endothelial cells clearance function; ii) modulate Aβ accumulation within the brain, a key contributor to AD pathology; and iii) promote neuroprotection from Aβ-associated damage and death, thereby slowing cognitive decline.