ESR1 and breast cancer: We compared several EO “variants”: EO cells “educated” using MDA-MB-231 human triple-negative breast cancer conditioned media, EO cells “educated” using MDA-MB-231BRMS human breast cancer metastasis suppressor conditioned media, EO cells “educated” using MCF-7 ER+ human breast cancer conditioned media, and EO cells “educated” using hTERT-HME1 human epithelial cell conditioned media (control).