To characterize the transcriptome of the transcription factor AP4 DLD-1 cells were infected with AP4 coding viruses for different periods of time. Adenovirus amplification and purification was performed as previously described (He et al., 1998). The minimal amount of virus needed to reach more than 90% infection efficiency was determined by monitoring GFP signals with fluorescence microscopy. DLD-1 cells were infected in serum-free medium with adenovirus for 3 hours. After removal an equal amount of medium containing 20% FBS was added.