PTEN expression and subcellular compartmentation are altered in the brain from Alzheimer’s disease (AD) patients [158,159,160,161], and the involvement of PTEN in regulating tau phosphorylation and amyloidβ (Aβ) peptide-induced neurotoxicity in human cell lines and mouse primary neuron cultures has been documented [93,95,161,162]. The gene discussed is MAPT; the disease is Alzheimer disease.