MAPT and Alzheimer disease: Currently, one dominant etiologic model of AD is the referred to as the “amyloid hypothesis” (Hardy and Allsop, 1991; Selkoe, 1991; Hardy and Higgins, 1992; Jack et al., 2013), which states that parenchymal Aβ builds up decades prior to the onset of clinical symptoms, resulting in a silent period termed preclinical AD (Sperling et al., 2011), followed by neurodegeneration and the accumulation of hyperphosphorylated tau.