Gvax/αCTLA-4 and CD25 depletion differentially impact intratumor T cell proliferation. Mice injected with anti-CD25 mAb 4 d before or after challenge with B16/BL6 were either left untreated or treated with Gvax/αCTLA-4 on days 8 and 11. 14 d after tumor challenge, tumors were isolated and analyzed for expression of KI-67 within the CD4⁺Foxp3⁻, CD8⁺, or CD4⁺Foxp3⁺ T cell compartments. As a comparison, KI-67 profiles from LNs of naive mice are also shown. Numbers on the top right of the histograms represent the percentage of cells expressing high levels of KI-67. Data are representative of 3 independent experiments (n = 3 mice per group).