PRF1 and non-small cell lung carcinoma: NK cells are instrumental in immunity against tumors by directly killing tumor cells and secreting cytokines such as IFN-γ, perforin, and granzyme B. To estimate the functional consequences of IL-35-mediated NK cell suppression, we performed co-culture experiments using NK cell supernatants and NSCLC cell lines (PC-9, A549 and H1975).