Serum Epo (a) and hematocrit (b) levels over time following a single intranasal administration of 3 × 1011 GCs per mouse of AAV2/5-CC10-rhEpo (black bars) or AAV2/5-CC10-lacZ (white bars). Values shown are mean ± SD (at 120 and 150 days, all but two animals had died due to effects of severe polycythemia).