Interestingly, we found that total IFN-γ positive leukocytes increased 6.2-fold in PD-1-/- mice after hindlimb ischemia, and the percentage of IFN-γ positive leukocytes in CD45+ subset also increased 3.0-fold in PD-1-/- mice (Figures 5A-D). The gene discussed is PDCD1; the disease is ischemia.