Researchers discovered a special fungus called Cladosporium cladosporioides living inside the roots of Gentiana yunnanensis, a traditional Chinese medicinal herb. This fungus is remarkably good at tolerating and neutralizing arsenic, a toxic heavy metal found in contaminated soils. The fungus uses multiple strategies to protect itself from arsenic damage, including moving the arsenic to its cell walls, converting it into less toxic forms, and activating protective defense systems.