The t(8;21) translocation occurs in around 12% of AML cases and leads to a fusion of the transcription factor (TF) AML1 (also known as RUNX1) and the co-repressor Eleven-Twenty-One ETO (also known as MTG8) resulting in repression of RUNX1 target genes in a dominant-negative manner (8). This evidence concerns the gene RUNX1T1 and acute myeloid leukemia.