Delivery of EPO in a mouse model of radiation-induced anemia. (A) Mice were injected with tet-epoECFC–based implants and kept in the absence of Dox for 1 week. Then, mice received sublethal doses of radiation (4 Gy) and were thereafter subjected to 3 different Dox regimes for 4 weeks (n = 4 each group). (B) The hematocrit in mice that did not received Dox (off) was compared with those subjected to permanent administration of Dox (on vs off; *P < .001) and an intermittent Dox regime (off vs on/off; †P < .001). The hematocrit in mice subjected to permanent administration of Dox was also compared with those on an intermittent regime (on vs on/off; ‡P < .001; §P < .05). (C) WBCs in mice subjected to each Dox regime were monitored and compared for the entire period of the experiment, with no statistically significant differences observed.