We show that chronic activation of 4-1BB signals induced the accumulation of IFN-γ-producing PD-1+CD8+ T cells in the secondary lymphoid organs of tumor-bearing mice by increasing the number of dividing CD8+ T cells, which was beneficial for suppressing tumor growth in the early phase of anti-4-1BB induction. This evidence concerns the gene TNFRSF9 and neoplasm.