A recent report from our group evaluating intratumoral delivery of checkpoint antibodies targeting CTLA-4, PD-1, and 4-1BB in combination with low-dose STING agonist in the TRAMP-C2 model of prostate cancer showed abscopal tumor regression with combination efficacy correlating with systemic antitumor immune responses [26]. Here, CTLA4 is linked to prostate cancer.