Establishment of UT-7/GM cells coexpressing Stat1α and Stat3. UT-7/GM cells were cotransfected with Stat1α and Stat3 cDNA. UT-7/GM and transfectant cells were deprived of growth factors for 24 hours and then incubated with GM-CSF (10 ng/mL) or EPO (10 U/mL) for 15 minutes. Nuclear extracts were then prepared from the cells, and an EMSA was performed using ³²P-labeled SIE probes.