Plane trees (Platanus spp.) are widely planted in European and Eurasian cities and are important elements in the forests of the eastern Mediterranean countries. Unfortunately, the future of European plane tree populations and plantings is severely threatened by Ceratocystis platani, an introduced, invasive fungal pathogen that causes canker stain disease. The participants of UB3Guard Training School recommend prevention as the main strategy to fight this disease. For more details, read the policy brief "Preventing the spread of the plane tree killer fungus, Ceratocystis platani"