The 4T1 syngeneic breast cancer epithelial cell line is a good murine model for TNBC because it lacks ER, PR, and HER2; can be grown in immune competent female BALB/c mice; is poorly immunogenic; shares substantial molecular features with human TNBC [11]; has rates of growth and metastatic patterns that resemble human breast cancer; and presents late-stage disease that is comparable to stage IV breast cancer [12,13]. The gene discussed is ERBB2; the disease is breast cancer.