The decrease in the levels or activity of protein phosphatase(s) that dephosphorylate tau also contributes to AD pathology (Braithwaite et al., 2012; Martin et al., 2013a); among these phosphatases, PP2A, STEP, and PTEN are FMRP targets (Figure 1A). The gene discussed is FMR1; the disease is Alzheimer disease.