The antitumor effect of CpG-Stat3 siRNA is immune mediated but does not depend on activation of host’s APCs. (A-B) NOD/SCID/IL-2RγKO or (C-D) Tlr9^−/− mice (n = 6) were challenged intravenously with 1 × 10⁶CMM⁺ AML cells and treated by using CpG-Stat3 siRNA or CpG-Luc siRNA or left untreated as in Figure 2. (A,C) Stat3 gene silencing was confirmed by qPCR; (B,D) percentages of GFP⁺c-Kit⁺ AML cells in different organs were determined by flow cytometry. Shown are means ± SEM from two independent experiments. Statistically significant differences were indicated by asterisks: ***P < .001; **P < .01; *P < .05.