Abnormal hematologic parameters of peripheral blood from Phd2 CKO mice. (A-D), Phd2 CKO and Phd2^f/f control mice were all treated with tamoxifen at 6 weeks of age and analyzed after another 6 weeks. Red blood cells, hemoglobin concentrations, hematocrit values, and white blood cells were all significantly increased. n = 6. **, P < 0.01. (E) Time course of serum Epo level increases as measured by ELISA. n = 3 at each time point. (F) Time course of increases in hemoglobin concentration. n = 3 at each time point. Error bars represent SEM.