Schizophyllum commune is an edible mushroom with health benefits, but cadmium pollution threatens both the fungus and human health. Researchers discovered that when exposed to cadmium, the mushroom produces a signaling molecule called nitric oxide that makes its cell wall enzymes more active, causing cadmium to accumulate in the cell wall and damaging the fungus. By controlling nitric oxide levels, scientists could potentially make these fungi more resistant to heavy metal pollution and safer for consumption.