PDCD1 and hepatocellular carcinoma: As shown in Supplementary Table 2, programmed cell death protein-1 (PD-1), cytotoxic T lymphocyte antigen 4 (CTLA-4), T cell immunoglobulin and mucin domain-containing-3 (TIM3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), CD8B, CD27, CD96, CD40 ligand (CD40LG) and TNF receptor superfamily member 4 (TNFRSF4) expression levels were upregulated, whilst adenosine A2a receptor (ADORA2A), CD33, killer cell lectin like receptor C1 (KLRC1), lymphocyte Activating 3 (LAG3), programmed death-ligand (PD-L1), Siglec 7 and Siglec 9 expression was downregulated in HCC.