ESR1 and breast cancer: We used immunohistochemistry to evaluate estrogen receptor, progesteronereceptor, human epidermal growth factor receptor 2/neu,androgen receptor and aldehyde dehydrogenase 1 (ALDH1) expression among WA(n = 153), AA (n = 76), Ethiopian (Eth)/East African (n = 90), and Ghanaian(Gh)/West African (n = 286) patients with breast cancer through aninstitutional review board–approved international researchprogram.