Representative etoposide-induced breakpoint sequence junctions. Left panel: representative sequence junctions of translocations of MLL gene to heterologous chromosomes. Red indicates sequence 3′ of the breakpoint junction, and green indicates sequence 5′ of the breakpoint junction. Right panel: representative sequence junctions of MLL PTDs. Underlined red sequences indicate overlapping homology between fusion partners. Bold black numbers indicate insertions. Numbers in brackets correspond to nucleotide lengths of longer insertions or homologies. For instance, in the top clone, a 2.1-kb PTD was produced following an Alu-Alu fusion with 23 bp overlapping homology.