PDCD1 and hepatocellular carcinoma: In the present study, we found that PD-1, CTLA-4, TIM3, TIGIT, CD8B, CD27, CD96, CD40LG and TNFRSF4 expression was upregulated, whilst ADORA2A, CD33, KLRC1, LAG3, PD-L1, Siglec 7 and Siglec 9 expression were downregulated in HCC.