The percentages of luminal A intrinsic subtype in TPBCs (TCGA, 50.6%; GSE2603, 40.5%; GSE2109, 43.3%) were much higher than those in ER+PR-HER2+ (TCGA, 16.0%; GSE2603, 15.4%; GSE2109, 0%) and ER-PR-HER2+ (TCGA, 0%; GSE2603, 0%; GSE2109, 9.1%) breast cancers. Here, ESR1 is linked to breast cancer.