As the peripheral blood of HNSCC patients has a reduced population of immunoregulatory CD56bright NK cells and an increased number of TIM-3+ and NKG2A+ NK cells compared to healthy donors, attempts are being made to increase the anti-cancer activity of the specific NK cell subpopulation and modulate NK cell activity [508,509,510]. This evidence concerns the gene HAVCR2 and head and neck squamous cell carcinoma.