Chidamide (1.00 μmol/L) alone did not have cytotoxic activity, but it significantly increased adriamycin-induced apoptosis in Kasumi-1 and HL-60/ADM cells (Fig. 2b), as well as in CD45 + cells and CD34 + CD38- stem/progenitor cells from AML patients (Fig. 2c). This evidence concerns the gene CD38 and acute myeloid leukemia.