AD-related cerebrospinal fluid (CSF) biomarkers, including amyloid-beta (Aβ) protein, total tau (t-tau), and phosphorylated tau (p-tau), have been established as core indicators to define the progressive stage in the AD continuum (McKhann et al., 2011; Jack et al., 2016). The gene discussed is MAPT; the disease is Alzheimer disease.