Background: MLLT1, also known as ENL (eleven nineteen leukemia protein), was originally identified as a gene involved in a recurrent translocation (11,19) with the mixed-lineage leukemia (MLL) gene. The MLL-ENL fusion protein has been found to associate with SWI/SNF complexes and promote transcription from the HoxA7 promoter. Additionally, from studies to identify proteins that associate with MLLT1, MLLT1 is suggested to play a role in histone modification and transcriptional elongation.