KMT2A and acute lymphoblastic leukemia: Our survival analysis of patients with ALL who received only chemotherapy showed that the 10-year EFS and OS of MLL-r positive children who received only chemotherapy were lower than those of the negative group, indicating that although children could enter remission with conventional chemotherapy, some children still experienced relapse after remission, resulting in a significant decrease in EFS, and although the relapse rate of children with MLL-r associated leukemia could be reduced by increasing the intensity of chemotherapy, the treatment-related relapse rate was significantly lower.