IFNG and head and neck squamous cell carcinoma: In HNSCC cells, Interferon-γ (IFN-γ), produced by CD8+tumor-infiltrated lymphocytes (TILs), was demonstrated to control the geneexpression of PD-L1 in tumor cells [28].Higher number of CD8+ TILs or TILs were discovered in HPV-positive HNSCCpatients compared with HPV-negative cases [28,38].