To explore the putative role of CXCR4 in NB malignant behaviour, we stably overexpressed CXCR4 by retroviral transduction in two NB cell lines with well-characterized growth properties: IGR-NB8, a non metastatic line, and IGR-N91, which forms metastases when implanted orthotopically [19]. Here, CXCR4 is linked to neuroblastoma.