Similar to AML with TET2 or IDH1/2 mutations, Rampal et al. identified reduced 5-hmC levels in WT1 mutant AML patients and they found that the overexpression of WT1 increased global levels of 5-hmC, whereas 5-hmC levels were reduced when WT1 was silenced (34). The gene discussed is IDH1; the disease is acute myeloid leukemia.