Further, the mutant IDH1 downregulated the DNA damage sensor ATM via methylation of H3K9 in a TET2 independent manner, leading to an impaired DDR and increased sensitivity to DNA damaging agents and in turn to an attenuated self-renewal of hematopoietic stem cells (HSCs) in AML [98] (Figure 7). Here, TET2 is linked to acute myeloid leukemia.