PDCD1 and neoplasm: In vivo imaging of intraperitoneal OC in mice revealed that the IPI‐549 (p < 0.001), IPI‐549+anti‐PD‐1 (p < 0.001), and PTX (p = 0.010) groups presented significantly lower tumor burdens than the control group did, whereas the anti‐PD‐1 group (p = 0.318) presented no significant changes in tumor burden.