The intracellular staining of the TDLN cells collected from MC38 tumor-bearing mice 4 days after a single injection of anti-IFN-γ mAb showed that the 4-1BB triggering increased the number of IFN-γ-producing CD8+ T cells by more than threefold compared with that of rat IgG-treated CD8+ T cells (Fig. 2c). This evidence concerns the gene IFNG and neoplasm.