Treatment of MO7e-G cells with the combination of G-CSF and SCF leads to synergistic induction of c-

fos. MO7e-G cells were factor starved overnight, then treated for 30 minutes with SCF (100 ng/mL), G-CSF (1 or 100 ng/mL) or both. RNA was harvested and analyzed by semiquantitative RT-PCR with primers specific for c-fos (upper) andGAPDH (lower).