(A-D) WT or CD70-/- C57BL/6 mice received 965 cGy irradiation on day -1 and were subsequently transplanted day 0 with (A-B) 4×106 BALB/c BM (n=5-8) ± 2×106 PanT (n=17-20), or (C-D) 4×106 BALB/c BM (n=5-8) ± 3×106 PanT (n=13-14). Data are pooled from 2 individual experiments. Weight loss (A, C) and survival (B, D) are shown. (E-F) WT or CD70-/- C57BL/6 mice received 965 cGy irradiation on day -1 and were subsequently transplanted day 0 with 4×106 BALB/c TCD-BM (n=4) ± 1×106 CD25- PanT (n=8). Mice were then monitored for weight loss (E) and survival (F). In (A, C, E) data are presented as mean ± SEM. Statistical significance determined by ANOVA in (A, C, E) and log-rank (Mantel Cox) in (B, D, F); *P<.05; **P<.01;***P<.001.