Certain studies show that chromosomal rearrangements like RUNX1-RUNX1T1 t(8; 21) in AML interfere with N-CoR/HDAC3 and enhance the pathogenesis process in these patients (Figure 2.A).21,22 Increased expression of HDAC3 has also been observed in chronic myeloid leukemia (CML). This evidence concerns the gene RUNX1T1 and chronic myelogenous leukemia, BCR-ABL1 positive.