PRF1 and neoplasm: In conclusion, the novel fusion protein melittin‐MIL‐2 exhibits strong anti‐tumor immune effect in lung adenocarcinoma cell A549 via activating the LFA‐1/ICAM‐1 and Fas/FasL pathways to enhance cytolytic activity, upregulating the secretion of IFN‐γ and perforin, and boosting LAK/NK‐like killing activities.