Dietary Supplement. Immune Support. Mushroom Mycelia Extract. Supports Healthy Natural Killer Cell Function*. Vegetarian Formula. Vegetarian/Vegan Product AHCC® is a proprietary extract produced from specially cultivated and hybridized mushrooms. According to extensive research in humans, as well as numerous non-clinical studies, AHCC® supports immune system function through its effects on macrophages and NK Cells. NK cells and the intercellular mediators they produce are critical for the maintenance of healthy cell cycle function. AHCC® has also been shown to possess antioxidant properties, and sup.