MAPT and Alzheimer disease: Discoveries such as the discovery of Tau protein and Aβ in cerebrospinal fluid, the first use of ELISA to measure T-Tau and phosphorylated Tau, and the combination of Aβ42 and Aβ40 in cerebrospinal fluid to improve the diagnostic accuracy of AD have been gradually revealed (Blennow and Zetterberg, 2018).