CD8A and intrahepatic cholangiocarcinoma: Low-level CD8 T-cell infiltration corresponds to shortened OS and shortened disease-free survival (DFS) (80–83).Among patients with ICC, those with a higher ratio of CD8+ PD-1High in CD8+ PD-1+ cells experience poorer postoperative survival (84).This might be due to the expression of PD-1High suggesting highly activated CD8+ T cells, which, however, demonstrate severe functional dysregulation and impaired IFN-γ secretion, leading to negative clinical outcomes (85).