Finally, the Rac1-PAK-LIMK1-Cofilin pathway has been implicated in several diseases that affect memory including Fragile X syndrome, Alzheimer's disease and Williams–Beuren syndrome57, and the discovery that Copine-6 regulates this pathway may provide new avenues for the better understanding of the molecular mechanisms involved in those pathologies. Here, RAC1 is linked to fragile X syndrome.