Cell cycle analysis. Parental UT-7/GM cells, Stat1α-transfected clones (A; clones 29 and 47), or Stat3-transfected clones (B; clones 5 and 29) were starved for 24 hours. The cells were subsequently stimulated with GM-CSF (10 ng/mL, left panel) or EPO (10 U/mL, right panel) and harvested at the indicated times for cell cycle analysis. The percentage of cells in G0/G1 was determined by a ModFitLT program. The data are the means of three independent experiments.