AREG and neoplasm: Flow cytometry revealed that IFN‐γ is the predominant cytokine produced by NK cells upon IL‐12, IL‐15 and IL‐18 stimulation (Figure S6A, Supporting Information), and that AREG‐KO NK cell–CM induced more cell death than WT NK cell–CM (Figure 7H), indicating that NK cell–derived AREG protects against IFN‐γ–mediated tumor cell apoptosis.