PDCD1 and neoplasm: We found that the tumor volume significantly reduced (effective tumor control rate of 83.3%, 5/6) in mice from the CX4945 plus anti‐PD‐1 therapy group; in addition, the weight of the tumor exhibited substantial decrease compared to the control group (P < 0.05), whereas there was no considerable difference in the body weight of the mice (Figure S5A–D, Supporting Information).