Although adjuvant therapies have been developed for several types of breast tumors, triple-negative breast cancers (estrogen receptor (ER)-, progesterone receptor (PgR)- and human epidermal growth factor receptor 2 (HER2)-negative) are particularly challenging to treat because of their highly aggressive nature and a lack of well-defined therapeutic targets on these cells [2]. The gene discussed is ESR1; the disease is breast neoplasm.