In AD, microglia encourage Aβ plaque formation, the phosphorylation of tau via the p38α MAPK/glycogen synthase kinase 3 (GSK3) pathway, the decreased clearance of Aβ, the reduced clearance of tau through increased competitive binding and the internalization of CX3CL1, the production of proinflammatory molecules and ROS, the structural and functional dysregulation of the BBB, and cognitive decline [49,64,65,66,67,68,69,70]. This evidence concerns the gene MAPT and Alzheimer disease.