This study selected seven prototype genes (AURKA, PLAU, STAT1, VEGF, CASP3, ESR1, and ERBB2) representing different biological processes, proliferation, tumor invasion/metastasis, immune response, angiogenesis, apoptosis phenotypes, and ER and HER2 signaling, respectively, and assessed the association between the expression of these seven gene modules and clinical variables and relapse-free survival of patients in each subtype of the breast cancer. The gene discussed is ESR1; the disease is breast cancer.