CSF Aβ42, tau, and/or phosphorylated tau on Threonine 181 [ptau(181)] are validated to identify AD pathology in an early phase of the disease and for differential diagnosis (Andreasen et al., 2001; Engelborghs et al., 2008; Le Bastard et al., 2010; Gabelle et al., 2011; Schoonenboom et al., 2012; Marelli et al., 2015). The gene discussed is MAPT; the disease is Alzheimer disease.