“…We did not perform a pharmacokinetic analysis of rhEPO levels in this study. However, considering that erythropoietin is normally present at 18 mIU/mL in mice, our injection schedule of 200 IU bolus injections three times a week could lead to appreciably higher than natural endogenous levels of erythropoietin. Our objective was to inject the HEPO and EPO formulations without dilution to get a readout on their relative immunogenicity, and as a consequence we had to use the smallest reproducible injection volume; however, these small volumes still translated to very high doses in mice.…”