Lupeol, a triterpene found in various vegetables, increases the proliferation and killing effect of NK cells on GC cell lines BGC823, N87, and HGC27 by increasing the expression of perforin, IFN-γ, and CD107a via the activation of the PI3K/Akt and Wnt/β-catenin signaling pathways (81). Here, PRF1 is linked to gastric cancer.