In breast cancer, treatments targeting tumors that depend on estrogen receptor (ER) signaling, aberrant signaling resulting from human epidermal growth factor receptor 2 (HER2) amplification and/or overexpression, CDK4/6 signaling and defects in DNA repair in triple-negative breast cancer (TNBC) have been particularly effective3. The gene discussed is ERBB2; the disease is triple-negative breast carcinoma.