FMR1 and fragile X syndrome: Two main paths however, seem to emerge as a link between the two pathologies in FXS: one is represented by the correct balance of the mGluR signaling pathway (Auerbach et al., 2011) and the other by the link with RhoGTPase activity and actin remodeling, represented by the two cytoplasmic FMRP interacting proteins CYFIP1 and CYFIP2 (Schenck et al., 2001, 2003).