The mighty chestnut tree once dominated many of our Appalachian forests, but was decimated by an exotic fungus in the first part of the 20th century. A few small groves of trees still remain in isolated pockets and living roots of some of the fallen ancient trees still try to send up new shoots. These shoots always die as soon as they are exposed to the fungus. How could chestnut trees be genetically modified to be resistant to the fungus and grow again?