Chromosomal breakpoints involved in MLL translocations in acute leukemia fall within an 8-Kb breakpoint cluster region (BCR), but breakpoints reported from t-AL and neonatal acute leukemia cases (<1 year) are concentrated in the most telomeric 1 Kb of this region, while breakpoints from de novo cases cluster towards the centromeric end of this region (Figure 4) [43,44,45]. The gene discussed is BCR; the disease is acute leukemia.