ESR1 and triple-negative breast carcinoma: By analyzing changes in the level of gene expression and immunohistochemical features, the expression of the estrogen receptor (ER+) or progesterone receptor (PR+), as well as that of human epidermal receptor 2 (HER2+) was determined, and triple-negative breast cancer (TNBC) was characterized by the lack of expression of the ER, PR, and HER2 [2,3].