In detail, a systematic review of 15 studies, including almost 14,000 BC patients, showed that TNBC is the most frequently infiltrated by TILs, with a 20% prevalence of lymphocyte-predominant BC (LPBC), followed by HER2+ BC (LPBC: 16%), with the luminal-like BC subgroup (HR+) showing the lowest degree of TIL infiltration, as well as the lowest prevalence of LPBC (6%) [7]. This evidence concerns the gene ERBB2 and breast cancer.