Leukemogenic mice that received a transplant of cS5^F as a model to characterize the transforming properties of Stat5. (A) Kaplan-Meier plot of mice that received a transplant of cS5^F (n = 8) versus mice that received a transplant of GFPv (n = 4). Mice that received a transplant of cS5^F died within 7 weeks after transplantation, while control GFPv mice remain disease free (followed for more then 10 months after transplantation). Thus, experimental mice that received a transplant of cS5^F were killed and analyzed 6 weeks after transplantation for all following experiments (dashed box). (B) White blood cell counts from mice that received a transplant of cS5^F (n = 8) and from GFPv mice (n = 4). Error bars represent SE. (C) Typical organic alterations of mice that received a transplant of cS5^F and control GFPv mice that were killed at 6 weeks after transplantation. Leukemic mice that received a transplant of cS5^F have a unique pathologic appearance with massively enlarged mesenterial lymph nodes (lymphadenopathy) and splenomegaly. (D) Splenic- and BM-cell extracts from 2 mice that received a transplant of cS5^F (Sp1, Sp2, BM1, BM2) or from control GFPv mice (Sp5, BM5, BM6) were analyzed by Western blotting with the indicated antibodies. Cell lysates from Ba/F3 cells unstimulated or stimulated with IL-3 for 30 minutes were also included as controls.