A) Unsupervised hierarchical clustering of 130 invasive tumors using 589 unique genes that are intrinsically variable (see Supplemental File 1) identifies luminal A, luminal B, normal-like, HER2 positive and basal-like clusters. Molecular subtypes, additionally classified by a nearest centroid approach are indicated by coloured bars (light blue: Luminal B; dark blue: Luminal B; green: Normal-like; orange: Basal-like; pink: HER2 positive tumors; grey: Unclassified).
B) Expression levels of p16, Rb, E2F3, cyclin E1, cyclin D1 and COX-2. The level of expression of each gene is relative to the median across all samples as represented by color saturation.