While alterations in hydroxymethylation patterns have not been as well examined, studies have indicated decreased hydroxymethylation across the genome in a variety of tumor types including adult and pediatric CNS tumors26,54,62–70, and mutations in hydroxymethylation-associated genes such as IDH1/2 and TET1/2/3 have been associated with certain tumor types like gliomas and acute myeloid leukemia62,71–74. Here, TET1 is linked to neoplasm.