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. This evidence concerns the gene IFNA1 and head and neck squamous cell carcinoma.