Gene-expression analysis of CD34 cells treated with IFN-γ. (A) Hierarchical clustering analysis of gene-expression patterns in CD34 and stromal cells over time. Each time point was averaged from 2 independent pools of CD34 or stromal cells. Genes were clustered on the horizontal axis and individual conditions on the vertical axis. IFN-γ N indicates control; IFN-γ Y, cells treated with IFN-γ. Blue-to-red scale indicates expression level from low to high. (B) The diagrams indicate genes that changed 2-fold or greater after 4 and 20 hours of culture. The top panel contains genes upregulated by IFN-γ; the bottom panel contains genes that were downregulated. Blue and yellow circles indicate genes changed in either 4 or 20 hours. Green circles indicate genes for which expression was changed at both time points.