KMT2A and leukemia: KMT2A translocationsassociated with infant and therapy-related leukemia can be mapped to an 8.3 kbbreakpoint cluster region between exons 8 and 11; the probe used to detectKMT2A rearrangements by Southern blotting was an 8 kbBamHI fragment spanning nearly that entire region (S2A Fig).Rearranged KMT2A was faintly detectable by Southern blotting at5 h after 1 μM etoposide treatment, whereas it was more prominent afterinjection of 10 μM etoposide (Fig 5A).