Analyzing EBV-specific responses in NPC tumor biopsy material, we found that TILs expanded for short time in IL-2 in the absence of exogenous stimuli were unable to lyse autologous EBV infected targets and only a minor proportion of the cells produced IFN-γ upon stimulation with the autologous LCL although the majority could be triggered to do so upon stimulation with PMA and ionomycine. The gene discussed is IFNG; the disease is neoplasm.