ESR1 and breast cancer: Using this same multi-gene classifying signature to interrogate cancer-adjacent normal breast samples acquired by The Cancer Genome Atlas (TCGA) program, Troester et al. identified 40% of samples with the Active transcriptome phenotype and showed in multivariate analysis that ER-positive patients with this peritumor microenvironment were 3-fold more likely to die of breast cancer within the next 10 years [4].