Finally, we found that NK/T cell subgroups in the HNSCC group highly expressed marker genes of depleted T cells such as CTLA4, LAG3, TIGIT, and HAVCR2, indicating that the inhibition degree of NK/T cells in the HNSCC group was stronger than that of leukoplakia (Fig. S7). Here, CTLA4 is linked to head and neck squamous cell carcinoma.