KMT2A and acute lymphoblastic leukemia: Therefore, this study further analyzed the prognostic factors affecting MLL-r positive ALL, and the results of Cox model multivariate analysis showed that T-cell phenotype, WBC ≥50 × 109/L and D15 MRD positive were independent risk factors affecting MLL-r positive children, which were consistent with the findings of Tomizawa et al [21] With the increasing maturity of conventional chemotherapy, most children with MLL-r ALL were able to achieve CR with treatment, and the mainstream treatment regimen was still chemotherapy.