Lentiviral expression of C/EBPα, C/EBPα-S21A, and C/EBPα-S21D in CD34⁺ cells. (A) Flow cytometric analysis for I antigen expression. Expression of the I antigen on the cells transduced with the virions prepared from the pLenti6 gene transfer vectors harboring full coding cDNAs for C/EBPα, C/EBPα-S21A, or C/EBPα-S21D, and those transduced with the virions prepared from the mock pLenti6 vector were analyzed using flow cytometry and detected with monoclonal anti-I antibody. Open and shaded areas indicate cells detected with anti-I antibody and FITC-conjugated secondary antibody and with FITC-conjugated secondary antibody only, respectively. The geometric MFI detected is shown on the top of each peak. (B) Expression profiles of IGnT transcripts. Real-time PCR was used to quantify the IGnT and GAPDH transcripts in the cDNA sample. Quantities of the IGnTA, IGnTB, and IGnTC transcripts were normalized to that of GAPDH transcript in each sample. Data were obtained from 3 detections; SDs are shown.