PBX1 and acute lymphoblastic leukemia: Based on cytogenetic aberrations, BCP-ALL can be divided into subtypes, e.g. t(12;21)(p13;q22) ETV6-RUNX1, t(1;19)(q23;p13) TCF3-PBX1, t(9;22)(q34;q11) BCR-ABL1, rearrangement of MLL (KMT2A) and high hyperdiploidy (≥50 chromosomes).