This was an in vitro study of Maitake mushrooms and prostate cancer. They found that the beta-glucan stimulated apoptosis of the cancer cells. The study also found that vitamin C potentiated this kill effect.
Study finds that maitake mushroom extract, MD-Fraction (a beta-glucan), has significant anti-tumor activity and anti-metastasis activity through NK activity, Antigen presenting cells, and through suppression of ICAM-1.