Our robust preclinical PDX models coupled to in situ 3D confocal imaging of native BM revealed that NG2 is crucial for MLLr-B-ALL engraftment upon i.v. transplantation, and that in vivo blockade of NG2 using either a specific inhibitor Ch’ase or an anti-NG2-specific antibody results in an extensive mobilization of MLLr-B-ALL blasts from BM to PB. The gene discussed is CSPG4; the disease is acute lymphoblastic leukemia.