While collectively, these studies suggest that EVI1 mainly associates and cooperates with HDAC140,65,66, HDAC240 (class I), or HDAC4 (class II)67, the number of studies validating EVI1-HDAC co-transcriptional complex in human 3q26 AML and cancer models is surprisingly low. This evidence concerns the gene HDAC9 and acute myeloid leukemia.