Among their many benefits, medicinal mushrooms have been shown to restore the competency of the immune system and to improve the outcome for people with a variety of serious illnesses, including cancer, hepatitis, and other conditions where effective nontoxiic treatment options are lmited."The Health Benefits of Medicinal Mushrooms" describes the most common supplemental medicinal mushrooms-including maitake, reishi, shiitake, and cordyceps-and their best clinical uses.