MAPT and Alzheimer disease: In one study, it was shown that oxidative stress causes the conversion of soluble amyloid into insoluble fibril form, which contributes to the progression of AD, and in another study, it was shown that the oxidation of Tau proteins, one of the characteristic features of AD, by free radicals in vitro may cause dimerization and polymerization of this protein [68,69,70,71,72,73].