CD8A and cholangiocarcinoma: However, in all three types of cholangiocarcinoma, lower density of PD-L1+DC-LAMP+ mature dendritic cells or PD-L1+DC-SIGN+ immature dendritic cells is associated with lower density of CD8+PD-1+ T cells either significantly or in a strong trend (Additional file 1: Figs. S13–S15).