MAPT and Alzheimer disease: Alternatively, cerebrospinal fluid (CSF) biomarkers, including amyloid-beta 1–42 (Aβ1-42), total tau (T-tau), and phosphorylated tau 181 (P-tau181) [11, 12], and positron emission tomography (PET) imaging scans [13–15] are effective for AD diagnosis, but because of the highly invasive nature of CSF collection and high cost of PET, using these biomarkers as part of a general physical examination to facilitate early diagnosis and therapeutic intervention remains challenging.