Moreover, assessment of tumor-infiltrating lymphocytes (TILs) has an important prognostic role in TNBC [30, 31] and in HER2+ disease [32, 33]; however, patients stratified according to any of these attributes experience a wide range of clinical outcomes, supporting the need to identify and validate additional biomarkers easily evaluated in clinical labs and that could add precision in distinguishing clinical progression and therapeutic response of each patient. The gene discussed is ERBB2; the disease is neoplasm.