We have previously suggested that NG2 expression may be dependent on the cell of origin where a specific MLL fusion initially occurs.14 This, together with the reported role of NG2 in the developing brain and in tumor cell migration/metastasis, prompted us to hypothesize that NG2 expression in iMLLr-B-ALL may contribute to the CNS disease/relapse frequently observed in B-ALL. This evidence concerns the gene CSPG4 and acute lymphoblastic leukemia.