T. pratense extract delayed the formation of BC tumors and increased apoptosis in 4T1 cells by stimulating T‐cell cytokines production (IL‐12 and IFN‐γ), reducing ROS generation by tumor cells, inhibiting 17‐β‐estradiol (E2) synthesis, and finally extending the survival of tumor‐bearing mice. The gene discussed is IFNG; the disease is breast cancer.