SCF/TPO surface-engineered LVs induce high levels of gene transfer in CB CD34⁺ short-term CFCs. CD34⁺ CB cells were incubated with TPO-displaying (G/TPOHA), SCF-displaying (G/SCFSUx), or codisplaying (G/TPOHA/SCFSUx) HIV-derived vectors for 72 hours. The gene transfer efficiency in the bulk CD34⁺ cell population (% GFP⁺ cells) and their CFC-derived transduced colonies (% GFP⁺ colonies) are shown. Data are shown as means ± SD, n = 3.