In the present study, we have designed and tested a microencapsulation-based drug delivery system to treat breast cancer cells with different receptor status (triple negative HCC1806, ER-positive HCC1428, and HER2-positive AU565 cells) with polyphenol-rich fraction (apigenin, caffeic acid, and luteolin) derived from pearl millet grains. The gene discussed is ESR1; the disease is breast cancer.