Recent studies have demonstrated that the GABAB receptor agonist R-baclofen (STX209) can improve locomotor activity and motor coordination in patients with FXS and modify the pathophysiology induced by FMRP deficiency including the effects on protein synthesis, AMPA receptor turnover, and dendritic spine density7, 8, suggesting a connection between GABAB receptor and FMRP regulation. The gene discussed is FMR1; the disease is fragile X syndrome.