Hormone receptor-positive/HER2− (HR+/HER2−) breast cancer presents with the best 5-year survival rate of 94%, followed by HR+/HER2+ cases (91%) and hormone receptor-negative/HER2+ (HR−/HER2+) cases (85%), while triple-negative (HR−/HER2−) breast cancer has the worst 5-year survival rate of 77% [1]. This evidence concerns the gene ERBB2 and breast cancer.