Breast cancers are characterized by the dysregulation and mutation of transcription factors such as ER-α, TP53, KLF5, SIX1, RUNX2, FOXO, MYC, and BRD4, which are capable of regulating epithelial-mesenchymal transition (EMT), the Warburg Effect, and mediating breast cancer cell resistance (4–9). The gene discussed is ESR1; the disease is breast cancer.