Figure 2.

Survival curves of recipient mice developing T-ALL. Survival curves are shown for cohorts of healthy nonirradiated C57BL/6 mice injected with cultured (day-12) ICN1⁺ cells derived from the bone marrow of 5-FU–conditioned mice (A) or unfractionated thymocytes (B) of the indicated Arf genotypes. (A) Twenty recipients of Arf ^+/+ and 15 recipients of Arf ^−/− bone marrow–derived cells in 2 experiments had a median survival of 34 days and 29 days, respectively. The differences in latency are statistically significant (P = .02 by log-rank test). (B) In 3 experiments, all but 7 of 30 recipients of Arf ^+/+ thymus-derived cells did not develop T-ALL, whereas 25 of 26 recipients of Arf ^−/− cells died of disease with a median survival of 30.5 days. Differences in latency are highly significant (P < .001 by log-rank test).