Phyllodes tumors are fibroepithelial breast cancers often found in adult women and can be very fast-growing and malignant. The cover shows a representative hematoxylin and eosin (H&E) stained section from a borderline phyllodes tumor used for targeted next-gen sequencing (NGS). The H&E is overlaid with copy number profiles from three malignant phyllodes tumors demonstrating high level copy number alterations (CNAs). Please see the article by Cani and colleagues (beginning on page 613) for more information.