PRF1 and neoplasm: Notably, after treatment, proinflammatory cytokine secretion was significantly increased by tumor‐border, but not by non‐tumor lung tissue slices, compared with the medium control, evidenced by higher levels of IFNγ (1.7‐fold), IL‐2 (1.4‐fold), and Perforin (1.5‐fold) (Figure 5A).