To further investigate the anti-tumor potential of the PD1+CXCL13+CD8+T cell subtype, we conducted in vitro cytotoxicity assays using PD1+CXCL13+CD8+T cells and PD1+CXCL13-CD8+T cells co-cultured with HNSCC cells. The gene discussed is PDCD1; the disease is head and neck squamous cell carcinoma.