A review of more than 18 mushroom species—including reishi (Ganoderma lucidum), cordyceps (Cordyceps militaris), and chaga (Inonotus obliquus)—highlighted their ability to modulate autophagy, the cell’s natural recycling system. Compounds like ganoderic acid and cordycepin triggered cancer cell death or boosted chemotherapy sensitivity by acting on key pathways. In some studies, reishi extracts cut colorectal tumor growth by up to 60%, while cordycepin killed lung cancer cells at very low doses.