In fact, changes in glial fibrillary acidic protein (GFAP), the main astrocyte marker, are present long before cognitive signs of disease [21] and are directly related to cognitive impairment [22]; see Figure 1A. Amyloid deposition occurs between the endothelium and the astroglial layer in capillary vessels, but spreads throughout the vascular wall in small vessels. This evidence concerns the gene GFAP and Cognitive impairment.