GM-CSF and Epo induce Bcl-3 mRNA expression in TF-1 cells. Total RNA was isolated from GM-CSF–induced or Epo-induced TF-1 cells and Northern blotting analysis was performed using 40 μg RNA from each sample. ³²P-dCTP–labeled Bcl-3 cDNA was used as a probe. 18s rRNA is shown as a control for equivalent loading.