Flow diagram illustrates the design of the MLL98 protocol. Each infant presenting with ALL was assigned to one of 2 subgroups at diagnosis according to the expression of CD10 antigen on leukemic blast cells. Patients were reassigned to subgroups based on the detection of MLL gene rearrangements after remission induction. Those with MLL⁺ blasts received 3 courses of intensification therapy followed by HSCT. Chemotherapy regimens for MLL⁺ cases are reported in Table 1.