Figure 1

Pairwise correlation of genes with cancer-associated gene expression. The correlation between all possible pairs of genes with cancer-associated gene expression (n = 232) were assessed to identify groups of genes that share a similar pattern of gene expression. Unsupervised hierarchical clustering was used to group correlated genes into 11 clusters, with the dendrogram threshold level to establish clusters indicated on the y-axis (green line). Genes were selected from the clusters in a parsimonious manner to predict lung cancer status using linear regression. The classifier genes came from specific clusters (outlined in blue), using 2–4 genes from each cluster. Clusters 4 and 7 contain genes which were up-regulated in lung cancer, and clusters 1, 2, 9, and 10 were down-regulated in lung cancer.