Scientists have developed a set of techniques to genetically modify the fungus Trichoderma aggressivum, which is usually known for ruining mushroom crops. This genetic toolkit allows researchers to edit genes in this fungus to study how it produces various compounds and why it affects mushrooms. By using modern gene-editing technology called CRISPR, researchers can now create specific mutations and study the fungus’s useful properties, such as its potential to protect crops or promote plant growth.