Researchers used UV light to mutate fungal strains that naturally produce powerful medicinal compounds called perylenequinones. These compounds show promise for treating cancer and viral infections through photodynamic therapy. Through careful mutagenesis and screening, they developed a superior fungal strain that produces over 2100 mg/L of these valuable compounds, far exceeding previous methods. The breakthrough highlights that focusing on multiple beneficial compounds rather than just one can lead to better commercial applications.