Researchers have discovered that dormant breast cancer cells can be “switched on” by a common virus, suggesting a potential trigger for cancer recurrence. This breakthrough sheds light on how certain viral infections might awaken inactive cancer cells, leading to renewed tumor growth. Understanding this relationship could pave the way for new strategies to prevent breast cancer relapse by targeting these viral triggers. The findings emphasize the importance of monitoring viral infections in cancer survivors and might revolutionize current approaches to breast cancer management.