MAPT and early-onset autosomal dominant Alzheimer disease: In Alzheimer’s disease, neurofibrillary tangles are formed by the abnormal aggregation of hyperphosphorylated tau protein, and previous studies have shown that 14-3-3 proteins are present in the neurofibrillary tangles of Alzheimer’s disease patients.26,27 In brain extracts, tau interacts with 14-3-3 isoforms beta and zeta.31 Since CSF p-tau is a biomarker of tau pathology, the correlation between CSF 14-3-3β and CSF p-tau indicates that CSF 14-3-3β is also associated with tau pathology.