HDAC9 and B-cell chronic lymphocytic leukemia: When DNA methylation was studied in paired diagnostic and follow-up samples from IGVH mutated and unmutated CLL patients, genes with prognostic significance including chronic lymphocytic leukemia upregulated 1 (CLLU1), lipoprotein lipase (LPL), zeta chain of T-cell receptor-associated protein kinase 70 (ZAP70) and NOTCH1, the epigenetic regulators histone deacetylases 9 and 4 (HDAC9/4), and DNA methyltransferase 3, beta (DNMT3B), were reported to be aberrantly methylated [14].