As PP2A is implicated in the pathogenesis of AD and is the major phosphatase for the tau protein (Goedert et al., 1995), we assessed the levels of phosphorylated tau (Ser-396) and found that it was significantly reduced following PBT2 treatment (PBT2 (−81%), P = 0.03) (Fig. 4c). This evidence concerns the gene PTPA and Alzheimer disease.