The oxidative stress leads to the progression of AD in three major ways: (i) the macromolecule peroxidation, (ii) Aβ metal ion redox potential, and (iii) the mitochondrial dysfunction, all of which affect cell homeostasis, the generation of ROS, and the up-regulate the generation of Aβ and p-tau. This evidence concerns the gene MAPT and Alzheimer disease.