Nevertheless, combination with anti-PD-1 resulted in significantly improved response rates and patient survival in multiple types of cancer.14,15,17,22–24 Furthermore, anti-CTLA-4 antibodies are capable of inducing long-lasting immunity in cancer patients.25,26 Therefore, CTLA-4 remains an important immunotherapy target, but major challenges remain in improving both safety and efficacy of anti-CTLA-4 mAbs. Here, CTLA4 is linked to cancer.