Unpaired t-test with equal or unequal variance (specifically for the analysis of cytokine expression in Fig. 5a ) was used to calculate two-tailed P value to estimate statistical significance of differences between two treatment groups in the whole study. One-way ANOVA followed by Newman-Keuls test was applied for comparison of multiple treatment groups. Two-way ANOVA plus Bonferroni posttest were applied to assess statistical significance of differences in tumor growth kinetics between multiple treatment groups. Statistically significant P values were indicated in figures and/or legends and labeled as with 1×10 5 B16 cells, n = 5-6. Statistically significant differences between CpG-Stat3 siRNA-and CpG-scrambled RNA-treated groups are indicated by asterisks. Similar results were obtained in 3 independent experiments. (b) Tumor growth inhibition by CpG-Stat3 siRNA involves NK cell-and T cell-mediated immunity. Mice with established B16 tumors were depleted of NK cell or CD4/CD8 lymphocytes prior to CpG-Stat3 siRNA treatment;