Breast cancer is commonly classified into four subtypes based on the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki‐67, namely Luminal A, Luminal B, HER2‐enriched, and triple‐negative breast cancers (TNBC).159. This evidence concerns the gene ERBB2 and breast carcinoma.