Identification of extratumoral microenvironment subtypes adjacent to breast cancer. (A) Unsupervised clustering dendrogram for 3,518 probes yields two main clusters of non-neoplastic tissues. Cluster 1/Active subtype (left, orange) is associated with high expression of genes involved in cellular movement, inflammatory response, fibrosis and low expression of genes involved in cellular adhesion and differentiation (See also Table 2 for gene ontology analyses). Cluster 2/Inactive Subtype has higher cellular adhesion and differentiation-related gene expression. Kaplan-Meier analysis and univariate Cox Proportional Hazards analysis (to estimate hazard ratios) were conducted comparing overall survival for Active versus Inactive. Results are presented for ER positive patients only (B) and for endocrine-treated patients (C).