We have obtained and characterized the polyphenol-rich fraction (apigenin, caffeic acid, and luteolin) from the pearl millet grains and tested its anticancer activity against phenotypically different breast cancer cells (triple negative HCC1806, ER-positive HCC1428, and HER2-positive AU565) using a microcapsule-based drug delivery system in vitro. The gene discussed is ESR1; the disease is breast carcinoma.