CD38 and acute myeloid leukemia: Consistent with the anti-leukemic activity of chidamide plus IDA observed in the CD34+CD38− KG1α cell line, co-treatment (48 h) with 0.75 μM chidamide and 20 nM IDA resulted in significant increases in apoptosis of primary CD34+ R/R AML cells (P < 0.05 vs untreated control, n = 12; Fig. 2c, d), although the responses varied among patients.