ESR1 and breast cancer: Much attention has been paid to the features of breast cancer in Africa and the parallels between breast cancer in indigenous Africans and in African American women, including a shift toward earlier onset; a tendency toward poorer outcomes; and an increased likelihood for the tumors to be negative for the estrogen receptor (ER), the progesterone receptor (PR), and/or the human epidermal growth factor receptor-2 (HER2) [1],[2].