FMR1 and fragile X syndrome: Reducing the expression of PIKE rescued phenotypes in Fmr1 KO mice, but PIKE reduction is thought, at least in part, to exert some of its effects in an mTOR-independent manner (Gross et al., 2015) Metformin, an AMPK activator, rescued FXS behavioral symptoms in both Drosophila and Fmr1 KO mice (Gantois et al., 2017; Monyak et al., 2017).