ChIP-chip analysis. (A-B) c-Kit⁺CD41⁺ cells in day 6 EBs were purified, seeded on OP9 stromal cells, and transduced with ether control or 3xFLAG-HOXB4 viruses. The cells were further cocultured with OP9 cells, and their growth was monitored. Control cells stopped growing after day 4 of culture (B). At day 12 of the OP9 coculture, c-Kit⁺ cells were purified by magnetic-activated cell sorting and subjected to a ChIP-chip analysis. (C) Distribution of genes in relation to the fold enrichment values (log₂). The dotted line represents the ChIP-chip threshold (> 2). (D) The average distribution of HoxB4-bound probes. The dotted line represents the normalized average signal over the entire chip. (E) GO analysis of the ChIP-chip assay results. The P value of each GO term is indicated.