This observation might add another argument to the importance of several genes like TET2/IDH1/2/WT1, NPM1 and RUNX1 in myeloid activation, as we and other groups have shown that the immature phenotype of AML is associated with TET2/IDH1/2/WT1 mutations [2,3]. The gene discussed is IDH1; the disease is acute myeloid leukemia.