This BCR-ABL1-like subtype is found in approximately 50% of so-called B-other cases, which are BCP-ALL cases negative for the sentinel cytogenetic lesions BCR-ABL1, ETV6-RUNX1, TCF3-PBX1, rearrangement of MLL, or high hyperdiploidy (51-65 chromosomes). This evidence concerns the gene PBX1 and acute lymphoblastic leukemia.