Erythropoietin expression and hematocrit levels of cynomolgus macaques injected intramuscularly with pseudotyped AAV2 vectors expressing isogenic EPO cDNA. Animals were administered AAV pseudotypes as indicated (AAV2/1, AAV2/5, AAV2/7, and AAV2/8) intramuscularly (1 × 10¹³ genome copies/kg) and were subsequently monitored for blood hematocrit (open symbols) and serum EPO (filled symbols), as measured by a commercially available ELISA. For each vector pseudotype, 2 animals were enrolled; their identification numbers are indicated. Serum EPO (mIU/mL) and blood hematocrit (%) are presented as a function of time after vector (days).