PDCD1 and cancer: The addition of anti‐PD‐1 antibody to anti‐CTLA‐4 antibody resulted in superior tumor control than treatment with anti‐CTLA‐4 monotherapy (****P < 0.0001; Figure 6), consistent with the superior efficacy of combination treatment vs. monotherapy in advanced cancer patients.2 Treatment of mice with established CT26 tumors with the anti‐RANKL/PD‐1 BsAb resulted in a significantly greater response compared with anti‐CTLA‐4 monotherapy (****P < 0.0001) and an equivalent tumor control compared with the combination of anti‐PD‐1 plus anti‐CTLA‐4 antibodies (n.s. difference between groups; Figure 6).