DNA microarray analysis identifies a homogeneous gene expression response of CLL cells after coculture with NLCs. (A) These heatmaps depict the top 10 genes that are up-regulated (top 10 rows of the graph) or down-regulated (bottom 10 rows) in 9 different CLL cell samples before and after 14 days of coculture with NLCs (14d NLC). The changes in gene expression are depicted for each gene relative to its expression level immediately after Ficoll isolation and CD19 purification and before initiation of NLC cultures (black squares). Shades of red and green indicate up- or down-regulation, respectively, of a given gene according to the color scheme displayed below the heatmaps. Displayed are the expression responses in 9 different CLL patient samples, as indicated on the top horizontal axis. (B) To illustrate the correlation between ZAP-70 expression and CCL3 and CCL4 induction, ZAP-70 gene expression in individual CLL cases was classified as high or low, as determined by microarray analysis and correlated with CCL3 and CCL4 expression before and after NLC coculture. In CLL cases with high ZAP-70 gene expression (cases 1, 3, 6, 7, and 9), NLC coculture uniformly induced a robust expression of CCL3 and CCL4, whereas in cases with low ZAP-70 gene expression the response was more heterogeneous (no induction of CCL3 and CCL4 in case 2; intermediate induction in cases 4, 5, and 8).