Mice were inoculated with 2×105 KPC cells via the hemispleen surgery, treated and sacrificed 14 days after KPC cell inoculation for isolation of tumor-infiltrating immune cells for flow cytometry analysis. (A.) Percentage of CD8+PD-1+Eomes+ T cells among CD8+ T cells. In a separate experiment, TILs were stimulated with mouse T-activator CD3/CD28 beads following isolation and then further characterized by flow cytometry. (B.) Number of IFNγ-expressing CD8+PD-1+Eomes+ T cells. Unpaired t tests were done. * p<0.05; ** p<0.01; ns, not significant. Numbers of T cells were normalized by the total cell counts of the single cell suspension of the livers. Data represents mean ±SEM in one representative experiment (n=3 per treatment group per experiment, repeated twice). (C,) A schematic model shows the role of anti-CD137 agonist antibody in regulating T cell function in pancreatic cancer.