Because the tumor-infiltrating progenitor exhausted TCF-1+ PD-1+ CD8+ T cells are documented to be the population that responds to the anti-PD-1 immunotherapy (9, 17), we administrated three doses of anti-PD-1 mAb at days 19, 21, and 23 in mice therapeutically immunized with either OVA + CTB or OVA + Porins (Figure 8A, top) (9). The gene discussed is TCF7; the disease is neoplasm.