We then further examined the expression of IDH2 in AML cell lines and primary AML cells that had been confirmed to harbor wt-IDH2 in comparison with normal peripheral blood mononuclear cells (PBMCs), and consistently found that wt-IDH2 protein expression was substantially higher in AML cells compared with normal PBMCs (Fig. 1c; Additional file 3: Fig. S1b, c). Here, IDH2 is linked to acute myeloid leukemia.