Compared to B-cell precursors, KMT2Ar ALL cells displayed significantly hypomethylated CpGs at enhancer regions, including HDAC4, which is associated with poor prognosis [42], DOT1L, involved in the development of KTM2Ar ALL [43], and MSI2, which is important for the prediction of poor survival in all ALLs [44] and for maintaining MLL-driven self-renewal [45]. The gene discussed is HDAC4; the disease is acute lymphoblastic leukemia.