Previous studies have identified DNA methylation of other tumor suppressor genes in AML, including retinoic acid receptor β (RARβ), estrogen receptor (ER), p15 (7), E-cadherin, p16 (7), glutathione S-transferase Pi 1 (GSTP1) (8), hypermethylated in cancer 1 (HIC1) (9) and death-associated protein kinase 1 (DAPK1) (10). Here, RARB is linked to acute myeloid leukemia.