Similar to the DNase I treatment, removing NETs from the TME using PAD4−/− mice improved the efficacy of anti-PD-1 ICI therapy, similarly to the DNase I combination therapy, resulting in a decrease in tumor growth and an improvement in overall survival rate; thus, our study provides mechanistic insights into combination therapy and uncovers the improvement in CD8+ T cell infiltration and cytotoxicity mediated by DNase I during ICI therapy. This evidence concerns the gene PDCD1 and neoplasm.