CTLA4 and intrahepatic cholangiocarcinoma: They identified that CTLA-4+ lymphocyte density was elevated in ICC tumors compared with the normal peritumoral hepatic tissue (p < 0.001) and that patients with a higher density of these CTLA-4+ tumor-infiltrating lymphocytes experienced a reduced OS rate and an increased cumulative recurrence rate when compared with patients that had a lower density of CTLA-4+ lymphocytes within the tumor (p < 0.001 and p = 0.024).