Alterations in plasma levels of amyloid-beta 1–40 (Aβ40), amyloid-beta 1–42 (Aβ42), or phosphorylated tau protein (p-tau) in different regions such as in threonine 181 (p-tau181), 217 (p-tau217), or 231 (p-tau231) have been demonstrated to be AD-specific and serve as early markers [8–11]. Here, MAPT is linked to Alzheimer disease.