CXCR4 and medulloblastoma: To assess the relevance of our model, we assessed the expression of WIP1, a metastatic medulloblastoma marker, which promotes migration through crosstalk with the chemokine CXCR4 and G-protein-coupled receptor GRK5.31,41 WIP1 was significantly upregulated in the metastatic medulloblastoma cell line (M2; D283Med) compared to non-metastatic (M0; MED6 and UW228-3) and early-stage metastatic (M1; D458Med) cell lines.