CTLA4 and breast carcinoma: To further investigate the combined efficacy of targeting HIF-1α during anti–CTLA-4 therapy, we performed similar drug-treatment experiments using immunocompetent C57BL/6 recipients and the E0771 breast cancer (Figure 4C) or MC38 colon adenocarcinoma (Figure 4D) model and observed synergistic effects in all models.