Identification of eight independent gene clusters. A) Each probe set is represented by a single row of colored boxes and single column represents each microarray. Cells with increasing up regulation colored with yellow of increasing intensity and increasing downregulation is colored with blues of increasing intensity. The similarity trees on the top (pluri.: Pluripotent; r. com.: reversible commitment; ir. com.: irreversible commitment) and on the left side, represent the similarity matrix of probe sets or microarrays. §: Samples treated 25 min. with FBS and LIF. B) Semi-quantitative RT-PCR of a selection of genes from clusters 1 to 7. Representative results, from 4 independent experiments, are shown.