FMR1 and fragile X syndrome: Recent work in mice shows glial FMRP is necessary, but not sufficient, for FXS model dendritic spine dynamics (Hodges et al., 2017), and co-cultures with astrocytes lacking FMRP illustrate delayed development (Jacobs et al., 2016), indicating that FMRP can act directly in glia as well as in neurons.