PRF1 and neoplasm: This subgroup is able to recognize and bind by interaction to its T-cell receptor (TCR) with the cognate antigen bound to MHC I, leading to the elimination of tumor cells by: synaptic exocytosis of granules composed of granzymes and perforins known as the “kiss of death”, or indirectly by secretion of cytokines such as tumor necrosis factor (TNF) or interferon gamma (IFNγ) (29).