Triple negative breast cancer cell is ER-/PR-/HER2-; HER2 overexpressing breast cancer cell is ER-/PR-/HER2+; Luminal B breast cancer cell is ER+ and/or PR+/HER2+; Luminal A breast cancer cell is ER+ and/or PR+/HER2-. The gene discussed is ERBB2; the disease is breast cancer.