PDCD1 and head and neck squamous cell carcinoma: It is also noteworthy that HPV-positive HNSCC patients in TCGA (The Cancer Genome Atlas) cohort with higher P-Tex score (5-year OS: 55.8% vs. 22.6%, p=0.02), proliferation score (MKI67-related genes, 5-year OS: 49.1% vs. 15.8%, p<0.001), exhaustion score (PDCD1-related genes, 5-year OS: 56.2% vs. 23.1%, p=0.05), or cytotoxic score (GZMB-related genes, 5-year OS: 55.4% vs. 21.9%, p=0.02) had better survival outcomes, whereas similar trends were not observed in HPV-negative HNSCC patients (Figure 2g–h, Supplementary file 5).