Given that aberrant expression of ETS family transcription factors is associated with poor prognosis in acute myeloid leukemia [31–33] and that integrity of some of these factors are important for MLLr leukemogenesis [34], it is likely that wild-type MLL1 functions in MLLr leukemia, at least in part, by regulating ETS function at active enhancers. The gene discussed is KMT2A; the disease is leukemia.