Although immune checkpoint blockade (ICB) therapies such as cytotoxic T lymphocyte-associated antigen 4 (CTLA4) and programmed death-1/ligand1 (PD-1/PD-L1) inhibitors showed promising antitumor effects in many cancers, they only exhibited a partial response and poor clinical efficacy in advanced OC [7, 8]. Here, CTLA4 is linked to cancer.