Scientists discovered a new antibacterial protein called CwhA produced by the fungus Aspergillus fumigatus that acts like molecular scissors, cutting apart the cell walls of harmful bacteria like Staphylococcus aureus. This protein is produced by the fungus when it encounters bacteria in the lungs during infection and helps the fungus fight off bacterial competitors. When CwhA cuts up bacterial cell walls, it creates fragments that alert the immune system, potentially boosting the body’s defense response against infection.