Moreover, research in recent years have shown that patients with central nervous system leukemia (CNSL), T-cell immunophenotype, low hypodiploid, BCR-ABL1 positive, E2A-PBX1/TCF3-PBX1 positive, or MLL rearrangements also had a poor prognosis (14–17). This evidence concerns the gene PBX1 and central nervous system leukemia.