Epo impairs B-lymphopoiesis at the pre-pro to pro B-cell transition. (A) B-cell differentiation as analyzed by FACS using the indicated surface markers. Impaired B-cell differentiation in the BM caused by both (B-C) exogenous rhEpo and (D-E) endogenous Epo as a result of PHZ-induced hemolytic anemia. Data are mean ± SEM and were collected 10 days after the first PBS, Epo, or PHZ injection. n = 12 for Epo and 8 for PHZ treatment.