Inhibiting Tim-3 in the absence of Tregs leads to decreased lethality. (A) B6 mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 3 × 10⁶ BALB/c or Tim-3^−/−–purified CD25⁻ T cells. Survival plot of BALB/c (closed circle) versus Tim-3^−/− (open circle) donor is shown (P < .001, n = 15/group). (B) B6 mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 10⁶ BALB/c CD4⁺CD25⁻ T cells. Survival plot of IgG control (closed circle) versus Tim-3-Ig (open circle) treatment is shown (P < .01, n = 8/group).