These 23 ESGs genes are highly co-expressed with epigenetic genes and also highly differentially expressed in distinct ALL phenotypes groups (CBX1, CBX5, CBX6, CBX7, PHLDA2, BAZ2A, BAZ2B, MYST2, MYST4, MECP2, SMARCA2, HDAC4, HDAC5, HDAC6, HDAC7A, HDAC9, SMARCA4, SMYD3, SUV39H1, DNMT3A, DNMT3B, PRDM2 and MBD2). The gene discussed is HDAC9; the disease is acute lymphoblastic leukemia.