As displayed in Figure 6E, PVR/TIGIT, NECTIN2/CD226, and FAM3C/PDCD1 were relatively more strongly expressed in Plac1+ epi‐CD4+ T cells than Plac1− epi‐CD4+ T cells and PVR was specific for Plac1+ tumor cells (Figure S12A,B, Supporting Information), which was subsequently validated in HNSCC cells in vitro and in the TMA cohort by mIF (Figure S13A,B, Supporting Information, Figure 6H). This evidence concerns the gene PLAC1 and head and neck squamous cell carcinoma.