STAT3 and medulloblastoma: Whether such a mechanism is conserved in medulloblastoma remains to be determined; our immunostaining and fractionation assays indicate substantial IGFBP2 accumulation in the nucleus of mouse and human medulloblastoma cell lines, but extracellular IGFBP2 signaling promotes and is required for the effects of IGFBP2 on STAT3 phosphorylation and EMT marker expression, as exposure of IGFBP2 knock-out mb cells to recombinant IGFBP2 results in rescue of STAT3 phosphorylation and N-cadherin protein, while treatment of wild type MB cells with IGFBP2 neutralizing antibodies has the opposite effect.