Retroviruses properly create Runx1, GATA2, and SCL proteins. (A) The efficiency of retrovirus-mediated gene transfer of Runx1, GATA2, or SCL was estimated by infecting NIH3T3 cells. Retrovirus-infected cells were evaluated by the expression of GFP (shaded histograms). Uninfected NIH3T3 cells are also shown as a control (open histograms). (B) Expression of individual proteins was confirmed by a Western blot analysis.