Figure 1: Gene expression programs in normal and malignant brain samples.
(A) Unsupervised hierarchical clustering of 38 samples including GBMs, OACs, ODGs, and normal brain specimens. Array elements that varied at least 2 fold from the median on at least 5 microarrays were included (2,490 cDNA elements representing ~2,000 genes). Only the array dendrogram is shown. Samples from different regions of the same tumor are indicated by brackets. Correlation coefficients between nodes are as indicated on the accompanying scale. (B) Unsupervised hierarchical clustering of 32 samples including GBMs and normal brain specimens. Array elements that varied at least 2 fold from the median on at least 5 microarrays were included (2,188 cDNA elements representing ~1,800 genes). The data are displayed as a hierarchical cluster where rows represent genes (unique cDNA elements) and columns represent experimental samples. Colored pixels capture the magnitude of the response for any gene, where shades of red and green represent induction and repression, respectively, relative to the median for each gene. Black pixels reflect no change from the median and gray pixels represent missing data. Groups of genes with common functional or biological themes are indicated. See our website (http://microarray-pubs.stanford.edu/gbm/) for a search-able version of this cluster.