ABL1 and precursor B-cell acute lymphoblastic leukemia: Still, a high frequency of CD34+/CD38− cells at diagnosis is associated with minimal residual disease (MRD) and poor prognosis in childhood B-ALL (14–16), and a CD34+/CD38− immunophenotype is typically observed in B-ALL with BCR::ABL1, which constitutes a high-risk subgroup of B-ALL (17).