Myeloprotection by CDD gene transfer in an in vivo murine transplant model. (A) Schematic overview of the gene transfer model, vector constructs, and chemotherapy application schedule used. Nadir levels of (B) peripheral blood granulocyte and (C) thrombocyte counts (mean ± SEM; n = 5) following high-dose (4 x 500 mg/kg, i.p., days 1–4) or prolonged low-dose (10 x 60 mg/kg, i.p., days 1–10) ara-C treatment are given. *P < .05 and **P < .01 denote significant differences by Student's t test (data compiled from Rattmann et al. [37] and Brennig et al. [38]; CDD: cytidine deaminase; IRES: internal ribosomal entry site; LTR: long terminal repeat; EGFP: enhanced green fluorescent protein).