Reishi

In a recent 2017 study, the traditional Chinese medicinal mushroom Ganoderma lucidum (Reishi) has exhibited a promising anti-cancer effect. Although the molecular mechanism of its effect on cancer cells is unclear, in both human and mice breast cancer cell lines, reishi suppressed breast cancer cell growth and migration. This indicates that Reishi may be a potential natural inhibitor for breast cancer. 

Y. Zhang. Ganoderma lucidum (Reishi) suppresses proliferation and migration of breast cancer cells via inhibiting Wnt/β-catenin signaling. Biochemical and Biophysical Research Communications, 488, 679–684. (2017)