PBX1 and acute lymphoblastic leukemia: The remaining B-ALL patients (76) (Table 1) expressed other Ikaros isoforms (Ik1, Ik3A, Ik2, Ik4, Ik5, Ik7, and Ik4A), 17 of them presented gene fusions as follows: ETV6-RUNX1 (10), E2A-PBX1 (4), BCR-ABL1 (2) and AF9-MLL (1).