This is a mushroom product with rice bran. According to a study of over 200 patients, MGN3 increased the life span of terminally ill cancer patients by more than 60%. [Townsend Letter for Doctors and Patients, Feb/March 2003, p.22]
MGN-3 has recently been taken off the market. In the government's first judgment against it's manufacturer, Lane Labs, a 1999 a million-dollar fine was levied against the company for making false marketing claims. There were no customer complaints, and this product was not deemed harmful or ineffective. The company continued to sell the products and fight the suit, so the government changed their tactics. In a crushing blow in mid 2004, a judge ordered that all of the products in question be destroyed and that Lane Labs refund the money they collected from all purchased products since September of 1999.
Another mushroom combination product, AHCC, may actually be more effective at boosting the immune system's ability to fight disease, at a lesser cost.
AHCC has much more research than the similar product MGN-3 from Lane Labs, and the research is independently done, with no conflict of interest among its researchers (the researcher for MGN-3 earned money from each bottle sold). AHCC has 500mg of active ingredient per capsule, twice what the MGN-3 product has, which means a lower cost to the patient. AHCC, not MGN-3, is the most popular mushroom-based extract used in Japan and the world today for immune support.