Although the infused CD34+ cell dose (1.0 × 106/kg) was below the generally recommended threshold for optimal engraftment (≥ 2.0 × 106 CD34+/kg), previous reports have shown that engraftment can still be achieved with doses in this range, often with slower hematologic recovery and prolonged anemia or thrombocytopenia (17, 18). The gene discussed is CD34; the disease is anemia (phenotype).