According to surface markers, researchers have separated breast cancer into four subgroups: HER2‐positive (HER2‐like), ER‐positive/HER2‐negative (corresponding to Luminal A and B), and Triple‐negative breast cancer, which is a type of breast cancer that does not have any of the receptors that are commonly found in breast cancer.1, 2, 3. The gene discussed is ERBB2; the disease is breast cancer.