Patient subgroups identified based on module expression pattern and their relapse-free survival. Panel A: two-dimensional clustering of the samples and the 17 modules in the GSE2990 dataset. Rows represent modules and columns represent samples, which are colored-coded by tumor grade, where blue, cyan, pink, and yellow correspond to grades 1, 2, 3, and unknown, respectively. Module expression is calculated as the average standardized expression of all genes in the module. The color scale bar shows the relative module expression level, where 0 is the mean expression level of a given module. Modules and samples are clustered independently by hierarchical clustering. Major module clusters (I, II, and III) and major patient clusters (a, b1, and b2) are labeled on the dendrograms. Panel B shows the survival analysis results for different patient subgroups. B1: group a versus group b, all tumor grades. B2: group a versus group b, limited to grade 2 (G2) tumors. B3: groups a, b1, and b2, all tumor grades. B4: grade 1(G1), 2 (G2), and 3 (G3).