CD8A and intrahepatic cholangiocarcinoma: Asahi et al. suggested that the number of CD8+ T cells in the outer edge of the tumor increased and then the number of HLA class I increased, and the role played by HLA class I expression was to present tumor antigen-derived peptides to the immune system, ultimately stimulating CD8+ T cells to show anti-tumor effects and optimize the prognosis of ICC 43.