Levels of the four cytokines in the tumor microenvironment. The tumor samples on day 5 post-treatment were harvested and intratumoral levels of IL-12 (A), IFN-γ (B), IL-10 (C) and TGF-β1 (D) were evaluated by ELISA. Control: control group; SLC: SLC group; SLC + anti-CD25: combination therapy group. Values were presented as mean ± SD; n = 5 mice/group. * P < 0.05, ** P < 0.01 for indicated comparison. Results were obtained in three independent experiments.