MAPT and Alzheimer disease: The CSF biomarkersAβ1–42, total tau (T-tau), and P-tau181 levels are corebiomarkers in the early diagnosis of AD.5−10 These become abnormal ones or maximal two decades before symptomonset.11,12 Furthermore, changes in cognitive functionresulting in cognitive impairment can be screened via neuropsychologicalexamination such as Alzheimer’s disease assessment scale-cognitive(ADAS-Cog) and the mini-mental state examination (MMSE).