(a-c) Anti-CRC efficacy of Camptothesome in subcutaneous MC38 tumor-bearing mice (tumors: ~200 mm3). Mice were intravenously injected once with Camptothesome (20 mg CPT/kg) with or without α-IFN-γ (intraperitoneally, 200 μg/mouse/3 days). (a) Individual tumor growth curves. (b) Average tumor growth curves. Data are expressed as mean ± s.d. (n = 5). (c) Tumor-bearing mice images from b were taken on day 22. (d) Representative flow cytometric plots of granzyme B+/CD8+ T cells (upper panel) or IFN-γ+/CD8+ T cells (lower panel), and respective quantitative analysis (right panel). Data are expressed as mean ± s.d. (n = 3, the tumors were randomly chosen from b on day 22). Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. *P < 0.05, ***P < 0.001, ****P < 0.0001.