In this study of estrogen receptor (ER)+ breast cancer patients, we identified DEGs for macro-dissected cancer tissues, malignant epithelial cells and stromal cells, defined as Macro-Dissected-DEGs, Epithelial-DEGs and Stromal-DEGs, respectively, and compared them to reveal the cellular source of Macro-Dissected-DEGs. The gene discussed is ESR1; the disease is breast cancer.