hEPO serum levels and reticulocyte counts in patients who received implants with the adenovector Biopump. (A) Measurements of differences in hEPO levels before and after Biopump implantations for patients in the low-dose cohort. (B) Measurements of differences in hEPO levels before and after Biopump implantations for patients in the high-dose cohort. (C) Measurements of the reticulocyte count of 4 patients from the high-dose cohort.