The factors affecting the recurrence rate for breast cancer includes young age at diagnosis (<40), negative for estrogen receptor (ER) status, negative for progesterone receptor (PR), positive for human epidermal growth factor receptor 2 (HER2), and triple negative for ER, PR, and HER2 receptors, as well as locally advanced stage (tumor <5 cm or positive lymph node involvement) [4]. Here, ESR1 is linked to breast cancer.