TNF and neoplasm: To assess polyfunctionality of tumor-specific CTL, tumor cell suspensions were incubated with SIINFEKL peptide, the cognate antigen recognized by OT-I CD8+ T cells (22) and produced by the AE17sOVA tumor cell line (14), for 6 h followed by intracellular staining for flow cytometry to assess the production of the pro-inflammatory cytokines IFNγ and TNFα.