PRKDC and neoplasm: Furthermore, while combination anti–PD-1 and anti–CTLA-4 blockade was ineffective against weakly immunogenic melanoma tumors in mice, adding DNA-PKi (NU7441) in conjunction with STGL and anti-CD40 (NU-SL40) or knocking out DNA-PK in tumors resulted in tumor regression in 75%–100% in mice.