TET2 and acute myeloid leukemia: TET2 is an α-ketoglutarate- and Fe2+-dependent dioxygenase that mediates DNA demethylation by catalyzing the oxidation of 5-mC to 5-hmC.8 As a tumor suppressor gene, TET2 was first discovered in acute myeloid leukemia (Abdel-Wahab and Levine, 2013), and its mutation was closely related to hematopoietic malignancy (Cimmino et al., 2015).