Fig. 5. STAT5B increases cell cycle progression through G1 in v-Src-transformed cells. NIH-3T3 cells stably cotransfected with various combinations of different forms of STAT5 and v-Src (see the Fig. 1 legend) at 7080% confluence were serum-starved for (A) 24 h or (B) 5 days. At the indicated times, cells were fixed with ethanol and stained with propidium iodide. The cell populations were analyzed for DNA content using a flow cytometer. The cell cycle distribution of the profiles was quantitated using the computer program for this flow cytometer and is shown in a bar diagram presenting the percentage of cells in S + G2 phases. The experiment was repeated twice, with each experiment performed in duplicate. Error bars, SD.