LNGFR expression on BM- and CB-derived CD34⁺ cells after gene transfer with a GALV-pseudotyped LNSN retroviral vector. Flow cytometric analysis of two representative transduction experiments into CD34⁺ cells derived from BM (A) and umbilical CB (B). The left panels show the isotype controls for nonspecific IgG1 staining. The CD34 and LNGFR expression on mock-transduced cells and LNSN-transduced cells is shown at the central and right panels, respectively.