Genomic rearrangements target the C-MYB locus in both human and mouse T-cell leukemias. Representation of the C-MYB locus in both the human and mouse genomes according to the UCSC database; note that the orientation of the mouse locus was inverted in this figure in order to maintain the orientation of the human locus and facilitate comparison. The ALDH8A1, HSB1L, C-MYB, and AHI1 genes are shown according to annotations in UCSC. The genomic rearrangements we described in this work in human T-ALL are indicated: breakpoints (vertical black arrows) of the 6 TCRB-MYB cases, and duplicated genomic regions (horizontal black bars) in the 13 T-ALL cases (TL01, TL29, TL38, TL40, TL49, TL59, TL61, TL63, TL66, TL76, TL77, CCRF-CEM, and MOLT4). The darker horizontal bottom line refers to a MYB^dup in addition to a larger 6q gain in MOLT4, leading to extra copies of the locus. Two FISH probes that were used for breakpoint mapping are shown. On the mouse genome (bottom panel), all the reported retroviral insertion sites of T-cell leukemias are indicated (vertical black arrows), based on data from the Retrovirus Tagged Cancer Gene Database.