One key function, identified long ago by Eastern medical science, is defense–that is, the body has the need and ability to defend itself against threats to its equilibrium, whether they be physical, emotional, or energetic. Having noted and studied the body’s defensive capabilities, Chinese doctors then explored the natural world to find ways of maintaining and enhancing them, and they discovered a number of ways to do so, including the administration of herbal remedies. Among these remedies is Ganoderma lucidum Mushroom (known to the Chinese as lingzhi and the Japanese as Reishi).