The results indicated that the tumor volume of the wild-type was lower than that of the Gpx4-KD group after IgG treatment, and the tumor volume of the wild-type was also significantly lower than that of the Gpx4-KD group after anti-PD-1 therapy, indicating a potential role of GPX4 in the responsiveness to PD-1 blockade (Fig. 6D, E). The gene discussed is PDCD1; the disease is neoplasm.