Based on our survival analysis results using the publicly available large panel of The Cancer Genome Atlas (TCGA) 779 breast cancer patient cohort [6] with clincopathological information, we further hypothesize that the upregulation of SERPINA1 in endocrine-resistant cells requires HER2 and has significant association with better survival outcome for ER+/HER2+ breast cancer. The gene discussed is ESR1; the disease is breast cancer.