Figure 5

cor ( K , C ) distinguishes sample subgroups in the absence of differential expression. Analysis of a simulated gene expression module consisting of 500 genes and 100 samples. Samples were assigned to one of three subgroups based on simulated disease status: “control” (n = 50; darkgreen), “moderate” (n = 25; red), or “severe” (n = 25; turquoise) (Methods). (A) Average linkage hierarchical clustering of samples using 1 – ISA (intersample adjacency) as a dissimilarity measure. (B) Distributions of module eigengene (ME) values by sample subgroup. Note that these distributions are not significantly different (P = 0.18, Kruksal-Wallis test), indicating that there is no differential expression associated with disease status at the modular level. (C) When depicted in terms of Z.K and Z.C, control and affected subjects segregated into two distinct groups (linear least squares regression lines in black [control] and red [affected]). (D) Heat map of simulated gene expression levels. Rows correspond to genes and columns correspond to samples. Green = low expression; red = high expression