Overall, our findings suggest that BCAT1 regulates DNA repair and that targeting BCAT1 could represent a promising therapeutic option, especially in combination with DNA-damaging agents, in T-ALL patients with NOTCH-1 activating mutations presenting high levels of BCAT1, mostly included in the cortical (CD1a+) immunophenotypical subgroup. Here, BCAT1 is linked to acute lymphoblastic leukemia.