CTLA4 and Familial prostate cancer: Immune Checkpoint Inhibitors (ICIs)—Ipilimumab are monoclonal antibodies targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4), belonging to a class of immune checkpoint inhibitors (ICIs) used in cancer therapy for conditions such as metastatic melanoma, ovarian cancer, renal cell carcinoma, and prostate cancer.