The therapeutic efficacy of dual CTLA-4 and PD-1 blockade is also diminished by macrophage depletion. Mice received i.d. challenges on the right flank with 2 × 105 B16-F10 tumor cells. Subsequently, i.p. injections of 100 µg anti-CTLA-4 and 250 µg anti-PD-1, either individually or in combination, were administered on days 3, 6, 9, and 12 after tumor challenge. The clodronate liposomes were injected on day 7 and day 14. (A) Individual tumor growth curves after B16-F10 cell challenge, with upper right numbers indicating tumor-free mice. Representative data from three independent experiments (n = 10 mice per group). (B) Tumor growth curves illustrate the average tumor volume in each group. Error bars represent means ± SEM. Data are representative of three independent experiments (n = 10 mice per group). (C) Representative survival curves from three independent experiments (n = 10 mice per group) were analyzed using the log-rank test. **P < 0.01.