BCR and acute lymphoblastic leukemia: In B-cell acute lymphoblastic leukemia (B-ALL), common translocations and number chromosomal abnormalities in children include t(12;21) [ETV6-RUNX1] with a rate of 25%, t(1;19) [TCF3-PBX1] with 5%, t(9;22) [BCR-ABL1] in 3% of ALL, and translocations involving the MLL gene with various partner fusion genes (5%).