PRF1 and neoplasm: (1) Lactylation suppresses NK cell activity: Lactylation reduces the expression of key cytotoxic molecules (e.g., Perforin, Granzyme B), weakening NK cell‐mediated tumor killing. (2) Impairs cytokine secretion: Lactylation decreases IFN‐γ secretion, reducing NK cell activation of antitumor immunity. (3) Promotes NK cell exhaustion: Lactylation upregulates inhibitory receptors (e.g., TIGIT, NKG2A), diminishing NK cell cytotoxicity.