For instance, Zheng et al conducted CyTOF profiling of immune microenvironment in hepatocellular carcinoma and revealed that leading‐edge regions exhibited an increase of tumor‐associated CD4/CD8 double‐positive T (DPT) cells, which synergistically expressed PD‐1/HLA‐DR/ICOS/CD45RO.173. This evidence concerns the gene PDCD1 and hepatocellular carcinoma.