Scientists sequenced the genome of a pear fungus called Penicillium paneum that produces patulin, a toxic compound found in moldy apples and pears. By analyzing its genetic blueprint, researchers identified 33 different toxin-producing gene clusters, with special focus on the 15 genes responsible for patulin production. The findings reveal which genes P. paneum uses to make patulin and how they compare to other fungal species, potentially helping develop better ways to prevent patulin contamination in fruit and fruit products.