We observed a similar regulatory phosphorylation of mammalian Msi2 when ectopically expressed in Xenopus oocytes, as well as the endogenous mammalian Msi2 in murine 32D myoblastic cells and human SH-SY5Y neuroblastoma cells in response to extracellular signals that induce cell differentiation. Here, MSI2 is linked to neuroblastoma.