PDCD1 and hepatocellular carcinoma: Specifically, early stage HCC tumors showed a significant increase in CD103+CD8+ TRM expressing high PD-1 and ICOS (C1) and CD127+ CD8+ and CD4+ TEM (C4 in CD8 and C1 in CD4) when compared to late stage patients (stage IIIA-B) (Figure 4).