DUX4 and leukemia: In these DUX4 rearranged leukemias, the double-homeobox transcription factor DUX4 is in most cases placed under the control of the immunoglobulin heavy chain enhancer, is expressed at high level and activates transcription of many genes including a novel ERG (v-ets erythroblastosis virus E26 oncogene homolog) isoform called “ERGalt”.