SCF-induced expression of pim1 transcripts in FDC2–wt-ER cells. To test whether the expression of pim1 transcripts might be modulated by SCF in FDC2 and FDC2–wt-ER cells, cytokines were withdrawn to promote accumulation in G₀/G₁ and cells were exposed to SCF at 11, 33, and 100 ng/mL (0.3, 1, and 3 nmol/L) for 60 minutes or to Epo at 0, 5, 15, and 45 U/mL (0, 1, 3, and 9 nmol/L) as a positive control. Total RNA then was isolated and levels of pim1 transcripts were assayed by Northern blotting. For comparison, c-myc transcript levels also were analyzed and equivalence in loading was confirmed using a probe for glyceraldehyde phosphate dehydrogenase (gapdh).