As described above, B cells with upregulated PD‐1 or TIGIT expression promote CD8+ T cell depletion, an effect that is also present in T cell IC.[28, 95]) For example, in vitro tumor cell line experiments have shown that PD‐1 expression on CTLs also has a role in negatively regulating tumor killing by CTLs themselves.[50, 96] Additionally, a transcriptome analysis revealed that in hepatocellular carcinoma, TIGIT‐expressing tumor‐infiltrating CD8+ T cells are often depleted, thus limiting the effector function of T cells.[97]. This evidence concerns the gene PDCD1 and neoplasm.