GVT activity is preserved in recipients of β₇^-/- T cells. Lethally irradiated (1100 cGy split dose) B6D2F1 mice underwent transplantation on day 0 with 5 × 10⁶ WT TCD-BM cells with or without the addition of splenic T cells. Recipients were given 1 × 10⁵ P815 murine mastocytoma cells as a separate intravenous injection at the time of transplantation. Survival is depicted as a Kaplan-Meier curve representing mice that received TCD-BM + P815 (•), TCD-BM +β₇^-/- T cells + P815 (▴), TCD-BM + WT T cells + P815 (□). Causes of death (GVHD vs tumor) for all recipients that died during the course of the experiment are shown in Table 1. Statistical analysis: ▴ versus □ (P = .005). Shown are combined results of 3 experiments (n = 30).