In relation to intrinsic subtypes based on immunohistochemical data, there was a trend toward greater fibroblast expression of extrinsic pathway markers in Luminal B (ER positive/ Her2 negative/ Ki67 high) vs Luminal A (ER positive/ Her2 negative/ Ki67 low) and in HER2‐postive and Basal (ER/PR/HER2 negative) versus Luminal cancers. This evidence concerns the gene ESR1 and cancer.