These genes include the tet methylcytosine dioxygenase 2 (TET2), mutated in 7–25% of AML, the isocitrate dehydrogenase 1 (IDH1, IDH2), mutated in 15–30% of AML and the DNA methyltransferase 3A (DNMT3A), mutated in 15–25% of AML (Shih et al., 2012; Conway O'brien et al., 2014; Greenblatt and Nimer, 2014). The gene discussed is TET2; the disease is acute myeloid leukemia.