Importantly, upon xenotransplantation into immunodeficient NSG (NOD-scid IL2Rgnull) mice, enCRISPRa-mediated TAL1 enhancer activation led to greater tumor burden with significantly increased bioluminescence signals of the luciferase-expressing T-ALL cells in mice 4 weeks post transplantation (Fig. 4i, j). This evidence concerns the gene TAL1 and acute lymphoblastic leukemia.