Distribution of circulating natural killer cells and T lymphocytes in head and neck squamous cell carcinoma.

Natural killer (NK) cells are capable of eliminating malignantly transformed cells without prior sensitization. In contrast to NK-cells, T lymphocytes possess antitumourous activity that is restricted to major histocompatibility complex (MHC) recognition. The aim of this study was to determine the causes of the different distributions of these cell types in the peripheral blood of patients with head and neck squamous cell carcinomas (HNSCC).