CD34 and leukemia: Consistent with the anti-leukemia effect of DS/Cu observed in CD34+/CD38− KG1α cells, treatment with 0.5 μM DS with or without 1 μM Cu-induced apoptosis of CD34+ AML cells (Figure 5a; P=0.012 and P<0.001 DS and DS/Cu versus untreated control, respectively; n=14), whereas Cu alone (1 μM) was unable to induce apoptosis (15.92±12.1% versus 11.45±6.8% for Cu alone versus untreated control, P=0.966).