Depletion of macrophages with clodronate liposomes abrogates tumor protection. (A) Initial experiment setup with the treatment schedule. (B) Individual tumor growth curves after B16-F10 cells challenge. The numbers on the upper right side represent tumor-free mice. Data are representative of three independent experiments (n = 5–10 mice per group). (C) Tumor growth curves depict the average tumor volume in each group. Error bars represent means ± SEM. Data are representative of three independent experiments (n = 5–10 mice per group). (D) Survival curves represent three independent experiments (n = 5–10 mice per group). (E) Modified experiment setup with early vs. delayed treatment schedules. (F) Individual tumor growth curves after B16-F10 cells challenge. The numbers on the upper right side represent tumor-free mice. Data are representative of three independent experiments (n = 10 mice per group). (G) Cumulative average tumor growth curves (left panel) and survival curve (right panel) from two independent experiments (n = 10 mice per group). Error bars represent means ± SEM. Survival curves were analyzed with the log-rank test. ns, not significant; **P < 0.01; ****P < 0.0001. Irradiated parental B16 tumor cells (Vac) were used as a control for the IVAX group.