Mutations and translocations of genes encoding epigenetic enzymes and histone proteins are frequently identified in cancer, such as TET2 and DNMT3A mutations, translocations of MLL and NUP98 genes in acute myeloid leukemia (AML), mutations of ARID1A and SMARCA4 genes in gliomas, SETD2 mutations in clear cell renal cell carcinoma (ccRCC), and oncohistone mutations in pediatric brain and bone tumors [4,5,6,7,8,9,10,11,12,13,14,15]. The gene discussed is ARID1A; the disease is acute myeloid leukemia.