GSK3B and neuroblastoma: Recently, Cole et al. have demonstrated that dephosphorylation of CRMP-2 at the GSK-3β-dependent sites (Ser-518/Thr-514/Thr-509) can be carried out by a protein phosphatase 1 (PP1) in vitro, observed in neuroblastoma cells and primary cortical neurons, and that the inhibition of GSK-3β by insulin-like growth factor-1 or the highly selective inhibitor CT99021 results in dephosphorylation of CRMP-2 at these sites [86].