AFF1 and myeloid leukemia: In support of such a model regarding MLL rearrangements, it was noticed that MLL transcripts can be founded in close proximity to actively transcribed translocation partners AF4 and AF9 in KG1 myeloid leukemia cells and Nalm-6 pre-B leukemia cells and AF4 and AF9 transcripts in close proximity to actively transcribed MLL (Cowell et al., 2012).