Across 109 studies and 53 mushroom species, compounds from reishi (Ganoderma lucidum), cordyceps (Cordyceps militaris), turkey tail (Trametes versicolor), and sun mushroom (Agaricus blazei) consistently killed leukemia cells by triggering programmed cell death and blocking key cancer growth pathways. One clinical trial showed turkey tail's polysaccharide PSK extended remission in leukemia patients by 418 days, while Sun mushroom's compound agaritine eliminated leukemia cells at concentrations as low as 2.7 μg/mL while leaving healthy cells unharmed. Clinical use is still limited by inconsistent extract quality and few large trials, but the depth of evidence across dozens of species makes medicinal mushrooms one of the most promising natural sources for future blood cancer research.