This study found that two types of plant fungi, Podosphaera fusca and Peronospora ficariae, can trigger asthma-like reactions in mice similar to known allergens. While these fungi produce weaker responses than the standard allergen ovalbumin, they still cause significant inflammation, immune activation, and airway changes. The research suggests these plant parasites should be added to the list of recognized allergens that may trigger respiratory problems in humans.