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). The gene discussed is RUNX1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.