CD4 and intrahepatic cholangiocarcinoma: Then, we conducted immunostaining of CD3 (pan-T cell marker), CD4 (T-helper cell marker), CD8 (cytotoxic T cell marker), CD68 (macrophage marker) and PD1/PD-L1 (immune checkpoint protein) in tumor specimen and paired para-tumor tissue of ten ICC patients without BTS, ten ICC patients with NHL stone and ten ICC patients with HL (Figure 5A/B/C).