Most of available data focus on early BC, where TILs have proved to retain a strong prognostic value especially in triple-negative (TN) and human epidermal growth factor receptor-2 (HER2) positive BC, when assessed on hematoxylin and eosin-stained (HES) sections of primary tumor in accordance with International Immuno-Oncology Biomarker Working Group recommendations [2–9]. This evidence concerns the gene ERBB2 and breast cancer.