Figure 2.

Ward's hierarchical cluster analysis of time-dependent gene expression patterns in the lungs of E. coli challenged versus control baboons. a: Differentially expressed genes were used in the hierarchical clustering analysis by Spotfire DecisionSite 8.1 (Spotfire, Sommerville, MA). Wards's method computes cluster proximity by the squared Euclidean distance between the gene cluster mean profiles. With this method ten clusters of genes with similar profiles were generated. See the Additional file 1 for a list of genes grouped in each cluster. b: Heat map of hierarchical clustering analysis. The hierarchical clustering process is represented as a tree, or dendrogram, where each step in the clustering process is illustrated by a join of the tree. Red color indicates a Z-score 1, green color indicates a Z-score equal to -1. The colors between red and green indicate Z-scores between 1 and -1.