To directly assess the impact of RUNX1 depletion on the engraftment and proliferative capacity of B-ALL cells in vivo we used bioluminescence imaging to follow leukemic propagation of RUNX1 shRNA or control shRNA-transduced cells (1:1 ratio) in a competitive setting (Fig. 7c). This evidence concerns the gene RUNX1 and acute lymphoblastic leukemia.