Besides, the expression of cytotoxicity-associated molecules, including granzyme, perforin, Fas/Fas Ligand and TRAIL, was higher in KLRG1+CD8 T cells than in KLRG1−CD8 T cells (Fig. 4g), suggesting that KLRG1+CD8 T cells might have higher cytotoxicity against tumor cells. Here, PRF1 is linked to neoplasm.