PDCD1 and hepatocellular carcinoma: After adjusted by purity, the results (Supplementary Figures 1A–C) revealed that the expression level of CFHR4, DNASE1L3, and SPP2 were significantly negatively correlated with PDCD1, LMTK3, and CTLA4 in HCC, but TAF6 was positively correlated with PDCD1, LMTK3, and CTLA4 in HCC.