CCND1 and neuroblastoma: In addition, CXCR4 overexpression increased the expression of miR-15a/16-1, induced the down-regulation of B-cell chronic lymphocytic leukemia/lymphoma-2 (BCL-2) and Cyclin D1, and activated MAPK signaling pathways, thereby promoting neuroblastoma (NB) cell proliferation, NB growth and treatment resistance.