IFNG and head and neck squamous cell carcinoma: Besides in vitro studies, recently, de la Iglesia et al. [11] found that in an HPV-negative HNSCC population, active smoking led to an immunosuppressive signature, presenting as a decrease in cytotoxic T-cell tumor infiltration and the reduced expression of genes in the IFNα and IFNγ response pathways compared with former and never smokers.