IFNG and neoplasm: CD3+ T cell functionality of R2 stage lesions has been evaluated by measuring their secretion of IFN-γ by intracellular staining following stimulation of single cell suspension of tumor cells with PMA/Ionomycin (Fig. 4c) and 10.4% of them (range 5–18%) produce IFN-γ after stimulation vs 2.3% when non-stimulated.