To this end, we used the community cohesion scores of 390 hormone receptor positive (ER+ and/or PR+, HER2-) breast cancer tissue samples (HR+ samples) and 99 triple negative breast cancer tissue (ER- and PR-, HER2-) samples (TNBC samples) from TCGA BRCA, which are the most distinct breast cancer subtypes based on immunohistochemistry (IHC) assay. This evidence concerns the gene ESR1 and breast cancer.