PBX1 and acute lymphoblastic leukemia: Interestingly, a population of sCD79b+ cases was detected in all subgroups investigated, including E2A-PBX1+ (5/24), BCR-ABL+ (5/20), MLL rearranged (MLLr) (2/13), TEL-AML1+ (7/17), and B-other (4/20) BCP-ALL patients.