Common in both acute myeloid leukemia (AML) and myelodysplastic syndromes, TET2 mutations drive hypermethylation patterns similar to those produced by DNMT3A loss-of-function mutations using DNA demethylation by conversion of 5-methylcytosine to 5-hydroxymethylcytosine (Figueroa et al. 2010). Here, TET2 is linked to acute myeloid leukemia.