Donor-derived IFN-γ facilitates GVL effects and promotes conversion to full donor chimerism in mixed chimeras after delayed DLI. Lethally (8 Gy) irradiated BALB/c mice were reconstituted with a mixture of TCD BALB/c plus WT (■ and ▲, n = 7 per group) or GKO (△ and □, n = 7 per group) B6 BMCs 8 weeks before DLI (ie, injection of 1.5 × 10⁷ splenocytes) from WT (■ and △) or GKO (▲ and □) B6 mice. All mice received 3 × 10⁵ A20 leukemia cells one week after DLI. Survival (A) and kinetics of donor chimerism in peripheral blood (B) from a representative experiment are shown.