Depsipeptide inhibited the tumor growth and prolonged the survival of leukemia-bearing mice in the large tumor burden therapeutic study. At the time of the initial therapy, the mice had sIL-2Ra levels of 10 000 to 25 000 pg/mL. Groups are the same as those described in Figure 4. The animals treated in depsipetide, daclizumab, and the combination of daclizumab with depsipeptide groups had significantly prolonged survivals compared with the PBS control group (P < .001). The combination of depsipeptide with daclizumab treatment significantly prolonged the survival of leukemia-bearing mice compared with depsipeptide alone (P < .01) or daclizumab alone treatment (P < .05).