Apart from known prognostic factors including age, white blood cell (WBC) counts, complex karyotype, antecedent hematologic disease and secondary leukemia [2], accumulated evidence has shown that the presence of somatic mutations in genes such as fms-like tyrosine kinase 3 (FLT3), nucleophosmin 1 (NPM1), CCAAT enhancer binding protein alpha (CEBPA), KIT proto-oncogene receptor tyrosine kinase (KIT), tumor protein p53 (TP53) [3] and DNA methyltransferase 3 alpha (DNMT3a) [4, 5] have clinical prognostic significance. The gene discussed is DNMT3A; the disease is leukemia.