CTLA4 and cancer: On the other hand, the use of immune checkpoint inhibitors (ICIs) in cancer treatment, such as monoclonal antibodies targeting the programmed death receptor (PD-1), ligand of programmed death receptor (PD-L1), and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) receptor, is widely used in treatment of many malignancies and is considered a revolution in cancer therapy [97,98,99,100].